I owe $434 on my iPhone 7 Plus. I’m eligible to upgrade. With that said, I don’t want to upgrade. I want to receive my iPhone X when I get it then pay off my iPhone 7 and unlock it and sell it. With that said, will I still be able to get the iPhone X through the Apple app under att without replacing my iPhone 7 because it’s not paid? If It does let me, will it be a new line or can I keep my current one?