Talking to Sprint Customer Service is pointless and hopeless, wasting both your cell phone minutes and time. You should file a complaint on
FCC (Federal Communication Commissions) website--Choose Form B (on billing). You do not have to submit any documentations at this point.
FCC will contact you when they need them.
I was going to post the website for you but found I am not allowed to post link so far--what a stupid forum rule?
Please search google with keywords
FCC and Complaint, you will find where to file.
Good Luck!
Actually, what I am thinking is it might be a good idea for all of us who have billing problems to file a class action against Sprint, just don't know how.