When I had Sprint for like 7 years, I needed a phone, which they would give me if I were a new customer. As an existing customer, they would not do this for me. I buy a phone, because at the time they had a good network in California and Texas. They started sticking a few bucks of bogus charges on my bill, every month for accessing the internet, which I could not do with my phone at the time. Two trips to the sprint store to "reprogram" my phone, numerous calls, finally I sent them a certified letter telling them that I had been keeping track, and would bill them for my time wasted, all of it, if it happened again. Shortly after that, the rules of phone numbers and cellular providers changed, so I was no longer stuck with sprint. My contract had been month to month for years, I notified them in writing that I was kicking them to the curb and went with a new company. Sprint sent me a bill for a few hundred bucks, then a 100% late charge after I ignored initial letter. I sent them a certified letter that delineated how much time I had wasted trying to resolve a chronic issue, unsuccessfully. I also enclosed an invoice that was very detailed, who I spoke to, date and time, how long on hold, trips to sprint store and how much I was billing them for each occasion. I would be happy to pay them the $400 they claim I owe them, right after they pay me for the $1200 they owe me for my time. I advised them I would be taking them to small claims court, which could get pretty expensive, as it would cost them $1000 a day

They caved immediately