The department of Education has a site on bullying, can't post the link but its in student support area, I couldn't actually read it myself today at the det site wasn't working (typical) but it might be worth a read if you haven't already.
I have also thought more about my comment about not complaining higher up, i think you should ring your local district office, the numbers are usually in the phone book and ask to speak to someone in Student welfare and explain the situation to them. Sometimes if a boss is as slack as yours sounds they need a kick in the a$$ and who knows, his staff may be frustrated with him about his nontackling of issues and be glad something gets done.