Please fire me. A customer left his credit card on the other side of the register counter where I...

Please fire me. A customer left his credit card on the other side of the register counter where I couldn’t see because he was in a hurry to get out of the store. He called corporate and said that I was the one that never gave it back to him because I was too busy “bullshitting with my coworker.” I was working alone that day. They gave him $500 worth of $25 gift cards to my store that he wanted handwritten to him, by me.