SAN FRANCISCO (AP) — An international honor society and Bank of America apologized Friday for a credit card offer to a feminist writer that referred to her by a sexual slur.

Golden Key International Honour Society spokeswoman Melissa Leitzell said on Friday that the group is looking into how the epithet ended up on the letter to Lisa McIntire.

The mailer, which said “Lisa Is A Slut McIntire, you’ve earned this special offer,” offered her a Bank of America credit card tied to her membership in the Berkeley chapter of the Golden Key International Honour Society.

Leitzell said the organization takes full responsibility and has apologized to McIntire. The freelance writer, a former communications staffer for one of California Lt. Gov. Gavin Newsom’s campaigns, tweeted a picture of her mail to one of the bank’s Twitter accounts Thursday.

“This error happened on our end. We are currently conducting an investigation of our systems to determine just what happened, and how it can be prevented from happening again,” Leitzell said in an email Friday.

The bank also has apologized.

McIntire did not respond to AP requests for comment, but told the Los Angeles Times she was “dying to know” how the phrasing wound up on the letter.

“What kind of got my adrenaline pumping is that I’m a feminist writer on the Internet, so getting a piece of mail that my mom is opening that says I’m a ‘slut’ made me think, ‘Oh god, which troll of mine is doing this?’” McIntire told the newspaper. “But I don’t think that’s what happened here. ... My working theory is that this is some data entry person (messing) around. I don’t think it’s aimed at me.”