Hi! I hear ya. Actually though, there is no such thing as "unknown" data charges. Believe me every data item charged has a reason behind it and you just have to find out what is causing those charges. Verizon should be able to explain every single charge so that you'll know exactly what that data use is and how it's happening. Once you know you just might want to adjust your plan to maybe cover those charges and ultimately lower that bill. I think dad is probably more upset that bill is always more than it should be and he's thinking you're doing something on purpose to make that happen. Once you can get Verizon to identify what is causing that overage . . . then ask them if there is a better plan that can cover whatever that overage is at a lower cost. Dad will be happy again when he see's a bill that is "consistent" so he can plan for it 
Whoa! Slow your roll down there junior . . . the OP is merely asking for an accounting of his data charges. He and every other member has an absolute right to a full acounting of charges. He nor the rest of us are trying to get something for nothing here. Every subscriber is entitled to a full acounting of precisely what their data charges are. Nobody said a word about not wanting to pay for something they ordered or anything of that nature. He needs a full accounting of his charges so that he can know if he needs a different plan.
