I upgraded from an iPhone 7 to X through AT&T Next. First through the preorder, which I cancelled when I found one in the store on launch day. Since that time, it's been silent from AT&T. I believe/know that I need to return my old phone, but I've received no emails, texts, boxes, reminders, etc. from AT&T. I believe that I may have a mailing label that printed out at the Apple store with my receipt, but that's it. Has anybody heard from AT&T? Do they send a box, etc? Or maybe we're supposed to know enough to send it back in our own box. Any help would be appreciated!