I kmow I have a thread dealing with a locked iphone, but could not find it, it has gotten buried in more recent posts. Well the seller recently agreed to refund me for an unlock code for my locked iphone 6s, right now it has an att sim and is locked and contracted to att. I want to unlock it and use it contract free with t-mobile. I was told that swift lock was a good one, I am looking for a good least expensive one that will unlock this phone. or is there a way I can do it for free? I tried connecting it in iTunes, but that did not unlock it.