The opposite happened to me—I asked for a plain burger and they still put all the nasty toppings underneath.
Only other bad experience I can remember is that I got a burger once that was cooked on the outside but not the inside. They took it off the bill but it was just a really odd thing to happen. Thankfully, I’d eaten a lot of appetizer bread beforehand so it wasn’t a huge loss.
Oh, and one time my family went to this Mexican restaurant in Disney World and they took an extremely long time to give us our food since they hated that we were on the meal plan, which made our bill $0 since everything was already covered. We gave them a bad tip then bolted out of there.