First, with respect to the cell phone plan, I would recommend you talk to your carrier to see if they will let you separate his number out and have him open his own account. If not, and you end up having to pay, you could sue him in Small Claims Court. As far as the truck is concerned, is the also titled in your name? If so, you would have the right to simply get the truck and sell it or surrender it to the bank assuming there's enough equity in it to pay off the loan. If not, you would again have the right to sue him in Small Claims Court depending on the amount that's at issue.
First, with respect to the cell phone plan, I would recommend you talk to your carrier to see if they will let you separate his number out and have him open his own account. If not, and you end up having to pay, you could sue him in Small Claims Court. As far as the truck is concerned, is the also titled in your name? If so, you would have the right to simply get the truck and sell it or surrender it to the bank assuming there's enough equity in it to pay off the loan. If not, you would again have the right to sue him in Small Claims Court depending on the amount that's at issue.