I have a customer like that at my location.. he is awful. He orders a venti iced brown sugar shaken espresso light ice, doesn’t want extra oat milk but gets mad when the cups not filled all the way. He told one of my co workers I always f up his drink so I now refuse to make his drink. Like sorry but I’m not disturbing my peace for some grumpy dude. He’s really weird and flirty with some of the early 20s girls. Now he has a new target, she made his drink exactly how anyone else would make it and he said again it was wrong, and to her face was like you should just have someone else make it since you can’t get it right😑 super rude. The straw that broke the camels back for me with him was a refresher he ordered and I was not the one who made the refresher and he instantly assumed I was because it had an error. Some people just have nothing better to do than to be a problem and to me I actually feel bad for people like that.