They're all scams.
If your good with lingo you can try and find out what provider he has, then you can play him by going to their provider and be like "Yeah im out of town i need to pay my bill" give them your number and there is a good chance they'll be like "so you're Mr. SMith" and then your all like "excuse me didn't hear you. then they be all like "Alex Smith, are you Alex Smith."
And just walk out.