Verizon Wireless Ron - manager under director of financial services Fraudulantl added a user under my account then charged me after they left! Internet

To make a long story short, my girlfriend (At the Time) switch to Verizon from AT&T back in 2011. I was not with her when she signed up for her new account. She was able to sign up but put her account under my main account. I never gave authorization for her to be under my account. I had knowledge of it when it first happened, but it would have been a hassle to get it switched. After all, She lived with me and we were going to be engaged. About 5 months ago we broke up and she moved to Vegas. She sent me money for her portion of the cell bill until she could get it transferred to another carrier or until she got it taken off from under me. So I call verizon and Everyone I spoke with at Verizon on the financial services department agreed with me, which is recorded on their end and mine . Again, they agreed my signature was no where to be found regarding her account and signing up for it. I then get transferred to Ron who says its a civil dispute and has nothing to do with Verizon. Are you kidding me? He said because I had knowledge it was fraudulent I had to pay it. So I am getting charged for VERIZON not doing their job?? They are the ones who fraudulently let her sign up for an account under my account.. not me! Again, everyone involved agreed I was to be compensated for that 150.00 charge. Until Ron got on the phone. How am I getting charged for Verizon signing up someone illegally? Just because I had knowledge of it doesn't mean I should get punished for verizon doing something fraudulant!!