"You could be in a restaurant and your card gets declined, what do you do? You have to call in," Colombo said. And that meant another chance to sell. "Sorry about the dinner, we'll fix it so you can pay for the dinner, and by the way, you have $20,000 available so let's find a way to get it into your checking account."
But what bothered Colombo most, she said, was being discouraged from telling military families that they were eligible -- by law -- to have their interest rates frozen at prime, currently 5 percent.
"We were told you cannot offer the Soldiers and Sailors Act rate unless they specifically ask. They must say 'Hi, I'm calling, my husband's on active duty, I'm aware of Soldiers and Sailors Act. What do I need to do?' But most Americans aren't aware of it," Colombo said.
Colombo says it was a stressful job that she hated.
"Ask any of my children," she said. "I would come home and I would be crying in the sink doing dishes."
Being a single mother of three with a mortgage to pay is what drove her "to keep my feet going forward every day."
On the other end of the phone were people like Josh and Jennifer Grant, parents of two young girls, Sierra and Sydney, who live in Waterville, Maine. Josh Grant is a self-employed trucker, Jennifer Grant works at a local hospital. They're $28,000 in debt.
Sitting at the family's kitchen table, Josh Grant pulled out his latest bill -- every few days he spends hundreds of dollars on fuel for his 22-wheel truck. He pays his bill weekly -- a total of $6,600 last month. But he spent $7,299 on fuel. That's how his bill grows -- not from spending on lavish dinners or expensive vacations, but from the high cost of diesel as he tries to make a living.
As he's showing"Nightline" the bill, we discover that he has gone $54 over his $21,000 credit limit -- and been charged a $39 over-limit fee.
"I didn't even see that, to be honest with you," he said. "When you get charged for being $50 over it's tough to swallow." They hope to pay off their debt in five to ten years. "That would be a good scenario," Jennifer Grant said.
Harvard Law professor and credit expert Elizabeth Warren said it's harder than ever to escape what she calls the "tricks and traps" of the credit industry.
"I wish I could tell you what you need to avoid the tricks and traps," she said. "But the reality is the game is loaded toward the credit card company. I can't read my own credit card contract. And I've taught contract law for more than 25 years."
How to avoid the hard sell? Strong use of the word "no," Colombo and Young said.
"Only if you gave me a very definitive, 'No, I'm not interested and thank you for calling but I have to go now," Young said. "That's how you got me off your back."
Young said at first he thought he was performing a "good service" for the customers. But that changed the longer he worked at MBNA.
"As time went by I began thinking I was doing a good job for the bank and the customers would have to fend for themselves," he said. He quit after seven years.
Colombo said she frequently waived or cut late fees, refused to sell what she considered useless credit protection and privacy monitoring services, even though she was told repeatedly to get her numbers up. She was marked down on performance reports for it, and eventually fired after four years on the job.
"I felt like I'd been released from prison," she said now. "I felt like I'd been liberated."
Colombo said she's back in college now, studying sociology and looking forward to "giving back to society."
Colombo left MBNA in 2005 and Young in 2002, both before MBNA was taken over by Bank of America in 2005.
Betty Riess, a spokesperson for Bank of America, said Colombo and Young's claims "do not reflect our practices. Bank of America has nothing to gain by extending credit to people who do not have the ability to pay us back."
She added that the terms of Bank of America's credit products are "clear and transparent," and fully disclosed up front.
Read the full statement from Bank of America here.