Natalie Johnson is a 27-year-old student and, until last week, worked at the River Center Macy's.
On Nov. 30, a teenager shopping caught her attention.
"I made sure to keep an eye on him because he was shopping for women's clothing," remembered Johnson.
She said she was convinced the shopper was a man. So when she saw him in the women's dressing room, she told him he couldn't change there.
"I had to just straight forward tell him, 'You're a man,' and of course that made him really got him steamed," said Johnson.
But the group of people he was with supported the shopper, arguing Macy's policy allows transgender people to change in the fitting room of the gender they associate with.
"I've made my choice the other day," Johnson told her manager. "I refuse to comply with this policy."
Johnson said she was let go.
Johnson filed a complaint with the Federal Employment Commission, claiming her religious beliefs prevent her from recognizing transgender people.
"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," said Johnson.
A response from the retail giant said, "Macy's does not comment on personnel matters. At Macy's, we recognize and appreciate the diversity of our customers and associates."
Johnson hopes the company will amend its policy.