sell it to someone else that would want the name for more moeny and let them deal wit it
I was in a exact situation few years ago, I had a gaming site, which i registered before a company even bothered to get the .com.
So one day, i get a email saying to hand over the domain name, but i told the guy fuck off or give me $$$ for it.
Then he gets all pissy and starts saying he'll sue me and shit.
so my host, who I kinda knew through chat, said he'd buy the domain off of me for $500 cuz at that tiem I was a scared 15 year old who didn't want a law suit, plus $500 sure was a lot. He then tells the guy that if he wants to fuck with someone, he can fuck wit him and his lawyers.
and then he gets an apology letter and then never talked to us again ;)