Legal Question in Credit and Debt Law in Tennessee

About all you can do is to pay the bill and disconnect the service. You can try to then sue your son-in-law, but unless there is some sort of written note or memo from him or signed by him that acknowledges it is his obligation to pay the bill or to reimburse you, your chance of success is about nil.

The problem you may run into is that if you terminate the cellphone service, you may very well be subject to an early termination fee that could run into hundreds of dollars.