If you get bad service, whether it's a rude waiter, cold/incorrect food or something else, the best and fairest course of action is to bring it to the manager's

If you get bad service, whether it's a rude waiter, cold/incorrect food or something else, the best and fairest course of action is to bring it to the manager's attention. They're usually pretty savvy about the real cause. But tipping a small amount just makes a waiter hate you.