Whatever you may have been told by Apple employees, you are wrong. There is a difference between an unlocked phone, which is what you get with the lUP, and a universally-compatible phone, which is what you appear to be expecting. You cannot use a phone, unlocked or not, with an incompatible network. AT&T and T-Mobile iPhone 7 models are incompatible with CDMA networks. It's as simple as that.