Seriously?

Customer: Can I return this?

A man I've never seen before is standing there holding a game that we sell

Me: Sure, do you have the receipt?
Customer: Oh, I don't have a receipt. I won it as a door prize this weekend at the ********* fundraiser.
Me: You won it?
Customer: yup.
Me: And you want me to return it?
Customer: Yeah. I can't figure it out so it's no good to me.
Me: I'm afraid I can't return anything with out a receipt. Perhaps you could donate it to the Literacy Council or the Salvation Army or something?
Customer: But it came from here. It had your business card on it.
Me: That would be because we donated it to the *********. You can't return it. No one paid for it to begin with.
Customer: So you won't return it because I didn't buy it?
Me: That's generally how it works. That's why we need a receipt.
Customer: Your service sucks!