Tmobile account.....?

[Devon S]

Basically I opened up a line of service on a separate individual for my boyfriends brother he ranked up the bill to $1,700 from him ordering Phones in which I did not allow. I tried disputing the charges with tmobile and they said that all the charges are valid and unless I would file a police report they would send me to collections. Now I tried contacting my boyfriends brother to discuss this but he refuses to pay he says its my account that Im responsible for it. if I go to the police what can they do?? theres no written contract that he will pay. someone help