Just put her "on the grease". The silent treatment. No more texts, facebook or any other source of communication. Chicks hate that and it'll twist her good. And it will do your heart and head alot of good not to have anything more to do with her - ever! You will have the upper hand and total control over the situation. End of story. I've had to do it a few times and each time they cried when I would not even ackowledge their presence when they wanted to talk to me. I totally ignored them and blew them off. Be cold as ice and move on.