What do you do when your child is being bullied by the coach on High School Basketball team.?

My son is on the JV basketball team and the coach curses, tells him he sucks, he's worthless, he should play like a black kid, etc.... I played high school and I understand you have to take a little of this abuse but the other kids are starting to gang up on him and bully him physically as well. As a parent I want to punch the coach in the face but I was wondering if someone had a better course of action? I just want them to cut him if he can't cut the mustard but the coward doesn't have the balls to do that, his answer is to bully him enough to quit.