good luck. i've had a dispute with verizon for over 2 years for a bill that came in at over a grand. they were supposed to have changed my rate plan to add way more minutes but, when the bill came, someone else there said, "we have no record of this...". pretty typical cellphone provider crap, actually.
there's a website I found while in the thick of it that people post such things to, and you'd be surprised at how much scamming these companies do to their customers. if you google for a while you might find it.