iPhone configured to only be used with prepay plans
This iPhone was locked to at&t they unlocked it. I went to Mint Mobile for 4 months. I tried to switch to Sprint and they are saying it's not compatible now and it's configured now to only be used with prepay plans. So I will never be able to use Sprint, Verizon etc. Why would the iPhone be set up that way?
[Re-Titled by Moderator]
iPhone 7 Plus