I have decided to get the 15 pro max! I'm currently paying for my 14 pro max on installment plans at AT&T for 36 months for $2.78/mo. I got $1000 off the 14pm cause of a trade in a device. I didn't plan on upgrading but I just decided to. Obviously I don't want to pay off my high balance on my 14pm which is $720. I know I can trade my 14pm into apple while still having a balance on the 14pm through at&t but can I still pay the same amount ($2.78) on the installment plan? So basically pay for the 15 pro max ($22.87/mo) plus the att installment balance ($2.78)?