I've got an iPhone 6S under T-mobile's service and I just saw T-mobile's offer of a free iPhone 7 for a 6 or newer, and I've got a question. I'm currently not on contract with T-mobile (so I bought the phone brand new straight from Apple). Would the offer still apply to me even if I'm not paying the phone off with a monthly fee? I have the receipt and original box with all the contents, if that may influence anything.