There's a breakfast and lunch diner we don't go to (I don't mention a name because it isn't a chain restaurant), not because the food isn't good, but because almost every time we've been there we've had to deal with someone's bad attitude. They usually didn't make food mistakes from what I saw, but one morning when we went there for breakfast my toast was almost black and smelled like charcoal. I asked the waitress if I could have another one, and she argued with me about whether the toast was "burned" or "just dark". I'm not particular about dark toast, but this toast was burned.
She finally sighed and took it back into the kitchen, and when she brought me my "new" toast it was the same two pieces with the charred outside scraped off. She plunked it down on the table, then left without a word. When she came back we were almost done, and she saw that I hadn't touched my toast. She commented on it, saying, "What, not good enough? It's not burned." I said that I had specifically requested a new piece of toast, that I was even willing to pay for it, and I didn't get any further before she picked up the toast plate and walked back to the kitchen grumbling about "a waste of food". We paid, informed the manager, and left with no intention of returning.
It's a shame, really. Their waffles were delicious.