So I want to upgrade my phone early, once 50% is paid and I order it; do I have to immediately send in my current phone? Is it 30 days from receiving the new phone that I have to send in the old one? The backorder date for the phone I want (which is 256GB Graphite iPhone 13 Pro Max) is 11/12/2021 which is 29 days from now. So would I be out of a phone for a month? How does that work?