Some pathetic script kiddie is harassing me, following me into every session I'm in. What do?

MODS, THIS POST DOES NOT BREAK RULE 4, IM ASKING FOR HELP GETTING RID OF THIS INDIVIDUAL, NOR DISCUSSING THE CHEATING ITSELF. PLEASE DO NOT DELETE.

I already blocked them, they still find me somehow. Rockstar doesnt seem to have banned any of their accounts because they always have the same name "Q-no complaining" or "Q-no begging" or something like that.

He teleports to me, kills me, and my horse just before I turn in my pelts to cripps. Of course he is invulnerable and one shots everything.

So, how do I deal with this bitch ass, lame, loser of a man-child?