Replying to What do you think of this?

At my stepdad's friend's kid's school, there is a black girl who is a bully to everyone. I think they are in nineth grade. Anyway just recently the black girl was picking on some other girl, calling them "white trash" and "honkey" and some other things. So my stepdads friends kid walks up to her and says "shut up you black bitch." Now he is suspended for a week because he stuck up for someone. He gets in trouble for calling her a black bitch, and she gets off no questions asked for calling a girl white trash and honkey. His parents went to the principal and complained, but he didn't do anything. What should they do?