T-Mobil is the WORST provider I have used
I do not know that the people at J.D. Power took into consideration when they rated T-Mobil so highly.
There are several problems with T-Mobil. The Treo 600 I purchased failed after less than one year. The T-Mobil store from which I got the phone (Framingham, MA) could not provide any clue as to where to send the phone or what to do. So, my ability to use the service stopped in October when the phone stopped. On a trip from the east coast to the west coast along I-80, I found coverage to be poor to non existent. No hotspots were available. I used the Treo primarily for email, and forgot the telephone number. After a move, the billing records were lost. Because of the way the website and the automated telephone systems are designed, there was no way for me to access customer service or technical support. For the same reason, emailing is impossible. The only place one can send email to to Investor Relations. Then the dunning calls started. Operators refused to provide either the telephone number of my dead Treo or the account number. I stopped paying for service I was not getting and that it was impossible for me to access. Since then, I have been subjected to an increasing number of harrassing phone calls. The account has been turned over to collection, and operators have lied to me about what would or would not be done to reconcile the matter. The conversations I have had with these morons would be good material for Crank Yankers, the Touch Tone Terrorists, or the Jerky Boys. T-Mobil calls with caller ID blocked. I have called the phone company to have calls with blocking rejected. Now, whenever a T-Mobil call comes it, I call the police and notify Verizon of the harrassment.
To put this in perspective, the amount at issue is about $320. That is the amount due for the period of time from when the phone went dead to I talked to the first moron about the account and terminated service.
Meanwhile, I switched to Sprint. By comparison, Sprint is a dream to deal with. There were some bogas charges that showed up on my bill, and the Sprint people quickly settled these out to keep my business.
In short, I have found T-Mobil to be among the handful of the very worst companies I have ever dealt with.