Ive had ATT for a very long time. recently i bought a new phone x and put the sim card into it. now I cant switch sim cards on the phone because it hasn't been 6 months since i put the chip into the device. how do i rid my device from the deathgrip of ATT and switch to T Mobile, and how to i swtich

I have been with AT&T since 1998, and never have has a problem.  I received an offer from T Mobile to pay off my phone (owe $650), and they would sell me that same phone for $400, and my monthly cost would be $50 / mo for the first year.  I did the math and I will save about $300/ over the 24 month

I traded in my iPhone 4s (in great condition) for a $200 Promotion Card that expired not even one year after the trade-in. I can tell from browsing the forums that MANY of us were unaware of the expiration date. Just wanted to know, did anyone actually have a success story and receive credit back on