Every restaurant employee, at some point or another, had had to deal with horrible, horrible customers. There are multiple online roundups of the worst of the worst, from people who think it’s appropriate to throw a fit and demand free food over some perceived slight to others who make outrageous demands and are never satisfied (they all invariably leave terrible tips as well). It’s basically guaranteed that terrible customers are bound to appear occasionally. So how do restaurant employees deal with them?
Sadly for them, employees are unable to simply refuse service to anyone, even an annoying customer (and when it does happen, those employees usually get into big trouble). They have to at least make a good faith effort to satisfy them, meaning that they can’t kick someone out because they’re “unwanted.”
If a customer becomes physically aggressive or starts hassling the other customers, then a manager can ask them to leave (without ever making physical contact with them), but if they’re just rude, employees have to suck it up and deal with it. A good tactic is to “kill them with kindness,” gritting your teeth, smiling, and trying to be as accommodating and professional as possible. That way, when they finally leave they might at least leave a decent tip. But they probably won’t.