A photo posted on Kelvin Lee's Tumblr page shows two ordinary restaurant receipts. But in the customer identification line, one receipt says "Ching" and the other receipt says "Chong."
Pictures of those receipts have gone viral on the Internet.
Lee says two of his Asian-American friends ordered meals at the restaurant and received the receipts showing the derogatory names.
Chick-fil-A admits the incident happened and has fired the worker who used the false names.
In a written statement, a representative for the fast-food chain says Chick-fil-A's reputation should not be tarnished because of the woman's actions.
"The individual clearly violated our operating standards," the statement reads. "The matter was addressed and discussed immediately with the guests on the spot; and a confirmation was provided that the employee was immediately dismissed for the individual behavior."
"I don't hear that happening very often, but as an Asian I wouldn't like it if someone called me Ching or Chong," said Shirley Kim of Santa Ana.