There are 4 things you can do when T-mobile places your phone in the Renegade device list that T-Mobile towers automatically block. You can say goodbye to using it on SOLAVEI, SIMPLE, ULTRA, FAMILY or GoSmart Mobile once T-Mobile IMEI blocks your phone. 1. It is no longer possible to use an imei blacklisted phone on AT&T. They have completely merged database and people can’t hop from T-Mobile to H20 or any other MVNO of AT&T like red pocket. 1. I don’t know the legality of changing your IMEI. The S5 imei cannot be changed now but s4 and note 3 and other Samsung phones can be changed. Some sites like theunlockpros claim they can unblock an IMEI but I believe it is illegal to do this and I don’t know how they get away with doing it but for your own good I would not use a service like theunlockpros that claim to repair/flash blocked phones.. In fact there are a few ripoffreport.com complaints against theunlockpros if you read them you will not want to do business with them as they claim to unblock and never deliver. Theunlockpros also makes people dowload files that do the actual changing of the IMEI so in reality they are using your computer remotely to do all the work so you are held liable for illegally changing your IMEI. http://www.ripoffreport.com/r/THE-UNLOCK-PROS/Select-StateProvince/THE-UNLOCK-PROS-THE-UNLOCK-PROS-they-do-not-deliver-what-they-promise-Nationwide-1109795 Pay off whatever you owe T-Mobile if you left without finishing your phone payments. Believe me they do IMEI ban for unpaid balances. That happened to me. Or just return the phone to T-Mobile if you have reason to believe the phone is lost/stolen. People are getting ripped off on craigslist by being sold phones with blocked IMEI’S. Word of advice people, put a sim card in the phone you are interested in buying from another person, and TEST IT! if it connects and you can make a call, then you are not blocked.