Get a friend if you have one, to videotape what this guy is doing to you, if that's possible, or tape it yourself. Then call the cops. Forget the school. Schools never listen until it's too late. Get evidence of this action and call the cops and file harrassment charges. Or, if the teacher has witnessed it, just call the cops and have the teacher back up what you are saying. I wish you the best of luck in getting this problem taken care of. What that guy is doing to you is harrassing you and you shouldn't have to put up with that.