Another good one from Not Always Right:
(The store I work in closes at 10:00 PM. It’s 11:30 pm and I’ve finished closing up shop, so I am about to leave. A customer comes up to the door.)
Customer: “Hey are you open?”
Me: “No, we’re closed.”
Customer: “Okay, but you ARE open, right?”
Me: “Sorry, ma’am, we aren’t.”
Customer: “But I want to buy something.”
Me: “Sorry, you’ll have to buy it tomorrow.”
Customer: “Fine! You f*%$ing scumbag!”
Me: *thinking: what a b****!*
Customer: “I HEARD THAT!”