Kids who bully and/or chronically tease other kids should be sent to reform schools. Unfortunately, those have been abolished.
Ok, then have someone physically superior to them, beat the snot out of them. After that, go to the bully's home and beat his/her parents. Do that every day for a couple of weeks. Even when they stop. Even when they apologize. They'll get the hint.
It's times like that when every kid's dad needs to be a mafia don.