Ew.
I think I've just about seen it all. I was at the pet store to get a slicker brush for my cat, and there was this woman standing at the counter, trying to return something and pitching a fit because they wouldn't give her a refund.
She was hollering and swearing and threatening to never shop there again, and threatening to tell everyone she knew to not shop there (typical snotty customer behavior).
I finally got to the counter to pay for my brush, and found out what she was trying to return - a mostly-eaten dog cookie. About two-thirds of it was gone, and the rest had teeth marks in it. She wanted her money back because her dog didn't like it.
What the fuck. Seriously, WHAT THE FUCK.