There's **** all you can do sir.
I haven't exactly been in that situation, but I have had similiar experiences, and seen other people suffer them. There is nothing you can really do.
*Fight em, either lose or get suspended. Not worth it, and they'll definetly get you back if they have any balls. Unless you're a uber l33t taekwondo man like myself.
*Do nothing. It's *****, but you'll either get off ok, or they'll still try and hurt you. I suppose it;s the best option.
*Tell an authority. HAHA, GOOD ONE!
*Burn his house down and hang him by the kidneys.
Well dude, I suggest do nothing, keep your cool but don't act tough. You should survive. I myself ended up becoming cooler and more witty, thus increasing my popularity and decreasing my enemys. You should try it.