Sprint Finalizes 'Bill Shock' Notification Service

What I really want to know where did the FCC get the authority to regulate billing practices in the first place?

The purpose of the FCC is to regulate the airwaves, to make sure that you don't have two radio stations trying to broadcast on the exact same frequency and that kind of stuff...

Nowhere in the FCC charter does it say that the FCC can regulate the business practices of the companies that use the airwaves....they just kind of grabbed that authority without any legal justification for it...