"Having worked in the food industry from a young age, I learned lessons pretty quickly on how to deal with unreasonable customers. One shift, I was working as the night lead, and we had a very angry customer from our drive through who came into the store after receiving his order. He was berating our cashier, and having heard this from the kitchen area, I immediately went out to try and calm the situation down. He demanded that he receive a full refund for his order because the meal he had ordered had ketchup on the sandwich, and he wasn't aware of that. I explained to him that while our drive through menu did explain all condiments on the sandwiches, I'd be happy to have another sandwich made to his order at no extra cost. While he still mumbled a few extra words after that response, I know he got the point that he was being very out of line to our staff for his mistake, and he apologized to our cashier after receiving his new sandwich. In any situation like this, it is important to maintain a professional approach, even when someone is out of line."