Natalie Johnson from San Antonio, Texas claims she was fired from her job at Macy's for telling a transgender customer that she could not change in the women's dressing room. (ABC News)

A Texas woman claims she was fired from her job at Macy's for telling a transgender customer that she could not change in the women's dressing room, according to ABC News' San Antonio affiliate KSAT.

The woman, Natalie Johnson, has filed a complaint with the Federal Employment Commission, saying that her religious beliefs prevent her from recognizing transgender people, according to KSAT.

Johnson, 27, was employed at the River Center Macy's in San Antonio until last week. She said a teenager caught her attention because the teen was shopping for women's clothing, but Johnson was convinced the shopper was male.

When Johnson spotted the teenager in the women's dressing area, Johnson told her she could not change there.

"I had to just be straightforward and  tell him, 'You're a man,' and of course that … really got him steamed," Johnson told KSAT.

The teenager's friends argued with Johnson, reportedly telling her that Macy's allows transgender people to change in the dressing room of the gender they identify with.

"I made my choice the other day," Johnson said. "I refuse to comply with this policy."

Macy's did not answer ABCNews.com's request for clarification on its policy regarding transgender customers and where they can try on clothes, but Macy's senior vice president of corporate communications and external affairs Jim Sluzewski issued the following statement:

"Macy's is very proud of our philosophy of diversity and inclusion, and we welcome all customers into our stores. This includes customers of all races, ethnicities, ages, genders, faith traditions, countries of origins and lifestyle preferences. We strive to ensure that each customer is able to shop in a discrimination-free environment."

Asked if she would handle the situation the same way if given another chance, Johnson said she would.

"There are no transgenders in the world. A guy can dress up as a woman all he wants. That's still not going to make you a woman," Johnson said. "If you're a man going into the women's fitting room, I will kindly escort you to the men's fitting room."