Get this guy to LEAVE ME ALONE!?

Ok this guy was talking to me last night and they seemed really nice so I gave them my number. Well it turns out that was a HUGE mistake. They won't leave me alone, I think they like me, we've never met except last halloween they may have chased me with a chainsaw at a haunted house, and they already put me on their top friends on myspace. They are extremely stalker-like and they seriously just need shut up. I want to give them the rejection hotline, but I've already given them my number so now I have no polite way to say leave me alone. Help!