I was working as a shift leader in a Dunkin' Donuts (spent two years in that hellhole) and dealt with my fair share of rude assholes. One particularly memorable day, a group of ladies came in during our busiest hour, just past noon. The line was almost out the door and we were short staffed so it was pretty hectic.
While they were ordering, one of them asked for a job application and started filling it out on the counter. She handed it back before they were done ordering and I stashed it on a shelf under the register and started making their food. They had a huge order and we did our best to get it out quickly, but it was obvious from the looks on their faces that we just weren't quick enough for their liking.
They sat down to eat their food, and the girl who just turned in her application got back in line. I spotted here right away; she was standing with a glaring face, crossing her arms and tapping her foot, trying her best to look obviously (almost cartoonishly) pissed off. So I motioned for her to come up to the counter, since I knew she had a complaint and I wanted to get it fixed right away. I assumed that in the shuffle we had messed up her sandwich or something like that; anyone who's worked in fast food knows that these things happen when it's chaotic.
I asked her what was wrong, and she pointed to her BOTTLED Mountain Dew and barked (definitely not an "indoor voice"), "THIS IS FLAT!" It was a bit accusing, as though it were my fault that the bottle of soda she just opened was flat. So I took it and told her to get another one out of the cooler, then check it to make sure it was good. After all that, she asked for a refund.
I said, as politely as I could, "Ma'am, I replaced your soda, sorry if there was an inconvenience but I don't think a refund should be necessary." [something like that, I don't remember my exact words]
So she stormed, pissed off, back to her table and started complaining loudly to her group about not getting a refund.
So, since I was having an awful day anyway and really could not see a bitch like this ever working for us, I grabbed her application from the register, walked it over to the lobby trashcan nearest to her table, crumpled it up and threw it away as she watched.
The look on her face was fucking priceless.