So my last payment for my 7 plus will be automatically deducted on 9/15, if I pre-order with the IUP. If tell it to replace this phone so I can pre-order since the payment is going through the next day do I still keep the 7 plus?
Yes because it is paid off. Although, I saw somewhere that your old loan is put on hold until you get your new phone so not sure if it will be paid automatically.