Unable to sign out of Netflix Account

When I first signed up with Xfinity my roomate added a Netflix account to my Xfinity account and I've been having problems with it ever since.  I've since kicked him out and everytime I move my service to a new address it automatically links his Netflix to my devices  I've called Xfinity multiple times because I was getting billed for his account and I've since had it removed but for some reason it still links his account whenever I move my service.  Now he has a pin on his profiles so I can no longer sign out of his Netflix account and I can't sign into my Netflix account.  What do I need to do to unlink his Netflix account from my Xfinity account so this doesn't continue to happen.