T-Mobile is a reliable provider in terms of service and prices that can be considered reasonable; however in terms of customer experience (CX) it is very bad or terrible. I can not understand that in times of technology seems a provider of the decade of the 80's. It is only enough to observe that if you want someone of loyalty to listen to you, you can only do it through a PO Box or by fax. A fax? Yes incredible. I imagine they do it to make contact as difficult as possible. In my case, I have been a customer with several lines for more than 20 years and I have never had a proactive call to personalize my experience and offer me an upgrade of a phone to change it. It is supposed to be a telco with information, technology and analytical capacity to have the necessary information to consider the case of loyal customers. Please! Instead I have to call forever to get the same answer: No, I'm sorry, you can't, you can't, I'm sorry and if you want you can send a fax or postal mail and file your claim. really???