So, I purchased a T-mobile iPhone. Went and got a prepaid sim card, used it for a couple of months, and on my birthday, no signal. After calling them over and over I finally got a rep. Well, he said it was blocked because of EIP no paid off on the phone. I asked him what the balance was and he couldn't tell me and told me I can't pay it. Only original owner can. So, I do know that since it isn't logged as stolen, it's only blocked on T-mobiles network, so I would like to somehow get this thing working with maybe ATT. What are my options for getting this phone unlocked to be used with an ATT sim card? I checked services, and of course, tmobile is the most expensive one at all the services(and takes the longest) Cheapest I found was like $140, and I don't want to pay that(and I'm not even sure that it would work with a blocked phone due to non payment) Any other options for using this T-mobile iPhone 5s with ATT sim card? Does anyone know if I took it to apple with the issues it's been having, and they replace it with a refurbed one. Will T-mobile block the EIP of the newer replaced one? How would they know? Anyone know a cheaper service that does unlocks for USA T-mobile iphones that are blocked due to non payment(EIP) Also, So, I had an old verizon sim card from an iPhone 4 or 4s. I cut it to size and inserted it into my iPhone. Well, after it restarted it went to activation(sim card is not activated) After trying to activate, it said invalid sim. Could this be because its a sim for Verizon(cdma) when my iPhone is tmobile(gsm) or is this a 100% certainty that my phone IS locked to tmobile and will NOT work with AT&T sim card?