Diane Cerulli's colleagues have always sought her out for health advice, and as a certified medical assistant, she did a "pretty good job" of diagnosing their aches and pains.
But she couldn't see the scam coming -- an online offer to get a medical degree by taking a test based on life experience for a mere $1,400.
"I always wanted to be a doctor, and I thought this was a dream come true," said the 59-year-old from Matawan, N.J.
After taking the multiple-choice test, Cerulli received a letter from Belford University, one of many online schools that purport to be accredited. It read: "You are now a doctor. Diplomas and paperwork will be mailed to you after you pay $1,400 for the degree."
Cerulli said, "Foolishly, I did that. I was told I could see patients and prescribe medicine. What was I thinking?"
These aspiring students were told by college admissions offices, potential employers and military recruiters that their credentials were worthless.
Online-based classes have become increasingly popular for students of all ages.
According to a 2008 survey from the Sloan Consortium and Babson Survey Research Group, 3.9 million students were enrolled in at least one online course in 2007, a 12 percent increase over the previous year.
Many of these online institutions are reputable, but many are being described as "diploma mills" that dupe those looking to advance their education.
"Today, my rational thinking is in full bloom, and I could get into a lot of trouble if I put up a shingle and called myself a doctor," said Cerulli.
The BBB has received 139 specific complaints about Belford High School and Belford University alone.
"It's amazing what people fall for," said Houston office spokeswoman Deana Turner, who is handling all the complaints.
"People who want to further themselves see something that looks really quick and easy," Houston's BBB spokeswoman told ABCNews.com. "People should know that if they get a college degree, there is a lot of time involved."
Belford's Web site touts: "Get a degree for what you already know!" It also offers "easy access" to degrees in all fields for "as low as" $249!"
For some time, Cerulli had been looking online for scholarships to medical school.
Belford offered a slew of degrees in accounting, physician's assistant and more. Ten minutes after inquiring online, she received a call from a "student counselor."
She recalled, "It didn't seem right to me, that you could pay for a degree. I repeated, 'Are you sure it's legal?' and he said, 'Absolutely.'
"I was so excited, and he was so convincing," she said. "I just went ahead and did it."
ABCNews.com contacted Belford at its offices in Humble, Texas, and initially talked to Calvin McCloy, who identified himself as a "student counselor." He said the school's principal, Marsha Marshall, "does not accept calls."
The BBB says Belford High School also may be using a double-scam technique to lure visitors to its site, according to the BBB.
The Web site BelfordHighSchoolScam.com, rife with grammatical errors and oblique testimonies, offers "questions and confusions in your mind being answered here."
"The site was obviously designed to persuade skeptics that Belford is a legitimate school," said Alison Southwick of the national BBB. "The only people who can benefit from this site is Belford itself."
The technique is common among work-at-home scams and offers for the popular acai berry, according to Southwick.
Both Web sites are registered through DomainsByProxy, a registrant that hides the actual registrant.
Another Belford Web site offers other sites a "fixed referral commission" by posting the school's banner. A retired Italian professor boasts that he has earned more than $50,000 by referring Belford.
"Professor Claudio Bernardo's passion for making education universal wasn't over," says testimony on the site. "Driven by his urge to help out students in every possible manner, he remained restless until he found an effective way to fulfill his desire of continuing to serve education."
A YouTube video of Belford High School is also linked to other reassuring videos, such as "Fake Degrees: No Thanks, Life Experience Degrees." A duplicate of that video, "Fast Graduate," urges, "Because you better don't waste your time with fake degrees, scams or degree mills." Belford is not the only online school under investigation.
James Phillips of Portsmouth, Ohio, struggled with getting ahead after dropping out of high school when he was only 17, working at a pizza parlor, furniture store and Wal-Mart.
At 21, married and with a 2-year-old son, he heard about a friend whose daughter had obtained a diploma online. Hoping to advance his career, he paid $270 to Jefferson High School Online and took a test.
"It was a basic math, reading and writing, an average test," said Phillips, who now works for the state's Department of Transportation.
After easily passing, Phillips was shipped his sheepskin. "It looked like any diploma I had ever seen," he said.
With that, he was accepted to Colorado Technical University, a legitimate online college where he was excited to start classes in business administration July 5.
Phillips had paid his fees and registration when the college called him to tell him he could not enroll because his diploma was not accepted.
He got his money back from the university, but not from Jefferson, and contacted the BBB.
Jefferson High School Online is owned by MMDS Ltd., based out of St. Kitts in the Caribbean. The same company operates a Web site called Vencer High School Online, which is a "replica" of Jefferson, according to the BBB.
"Their physical office is in Sonora, Mexico, and their post office address is in Nogales, Ariz., a huge red flag," said Nick LaFleur of the Southern Arizona BBB, which is handling the complaint about Jefferson High School Online.
Responding to a request for comment, MMDS "admininstration" wrote in an e-mail, "We respectfully decline participation in this project but we do proactively work to resolve all issues presented to us by customers and organizations such as the BBB."
The BBB has now closed down three fraudulent online schools -- but not Jefferson, Vencer or Belford.
"It's really disheartening because these people are trying to improve their lives, and you hate to see them taken advantage of when they are trying so hard," LaFleur told ABCNews.com.
"They give you a questionnaire, a kind of a hoax test, like asking what type of music you like and how often you listen to music," he said. "They say it will count toward your elective and life-experience credit.
"If you miss one, they give you a hint and three more chances," said LaFleur. "It's pretty easy to pass the test."
Such was the case with Debra Harris of Crockett, Texas, who dropped out of high school her junior year because she was pregnant. Now, the 42-year-old mother of three wants to get her diploma.
She turned to Jefferson when the ads popped up while she was searching for programs online.
"I knew something was wrong because the test was too simple," she told ABCNews.com. "It was multiple choice, and if you didn't get it right, you could go back and do it again. Everybody passes."
Still, she paid the $250 and the diploma arrived. But when she applied to Trinity Valley College, she was told her credentials weren't "good anywhere."
"I tried to call them [Jefferson], and there wasn't a legitimate phone number," said Harris, who lost her money but later got her General Equivalency Diploma (GED) from a state-accredited learning center.
"Some of these schools are accredited, but it's the acceptance of the diploma," said Michael Ormsby, president of the Oregon-based GED Academy, which provides BBB-approved online courses to prepare for the federal standardized test.
"The problem is, when you go to apply to another school, they do not accept the online test," he told ABCNews.com.
Meanwhile, Diane Cerulli considers herself lucky because she got her $1,400 back from Belford for her dubious medical degree.
"I called them and read them the riot act," she said. "I came to my senses."
"I felt like a fool," said Cerulli. "I just wanted it so badly."
To check out a university to see if it is accredited, contact the Better Business Bureau.
The U.S. Department of Education has a searchable database of accredited post-secondary schools, or those seeking a high school diploma can consult with their local junior college or community college for programs.
ABC News information specialist Nicholas Tucker contributed to this story.