I kinda feel bad that I wasn't fired for screaming at some stupid customer. Example:
"I don't want this anymore, why can't I get my money back?"
"Sorry, I can't return an item with a reciept and give money back. Best thing I can do is give you a gift certificate."
"But I want money back! What am I supposed to do with it?"
"Sell it on ebay for twice as much?"
"Look, I just want my money back, I've been in here many times, I bought it here and...."
"LOOK BITCH, I DON'T THINK YOU HEARD ME THE FIRST TIME! I CANNOT GIVE YOU CASH FOR THAT! IF YOU ARE SO FUCKING STUPID YOU DON'T UNDERSTAND ME, YOU DON'T NEED TO SHOP HERE!"
*proceeds to slap the customer out the door with a broom*
If there's any reason for getting fired, that one would be the best. At least you're going out with a bang.