Please Help: Pre-ordered in Error with SAME phone number on Apple and then ATT

[Apple1467]

I always reserve the iPhone at launc in the middle of the night. This year I needed to preorder for my brother two (we are on the same account each with our own line). I successfully preordered mine through Apple with their app but then shipping times slipped for his so we used ATT and got it for 11/3 delivery. But I mistakenly clicked to use my number AGAIN on ATT. Now I have one paid-in-full order from Apple with the same phone number as my ATT Next Preorder with ATT. I’m on the phone with ATT and they’re telling me I’ll have to cancel my preorder with them and reorder for the correct phone number (his) which will cause his to have a later shipping date. He doesn’t seem to think there’s a way to re-link my current ATT order to the correct number without cancelling. He said that one order from Apple or ATT will inevitably cancel when they try to ship (which is what I was trying to re-rote and prevent). I don’t know if calling apple would help to re-link the phone number for that Phone? Any advice on this before I lose my spot and allow him to cancel it? On the phone now...