iPhone 17 Pro Max data and transfer issues between identical models

I just got a new iPhone 17 Pro Max and IT support from the cellphone carrier has been with me trying to resolve the data connection issue for over two weeks. The team found nothing wrong on their side. I went into the Apple Store and they couldn't find anything wrong on the apple device diagnostic itself. The only other option was to replace the phone and have them tear down open the phone and see if there was anything internally that wasn't put together properly.

Anyways I went back to the Best Buy where I had ordered the phone and they tried moving my data and transfer over to a new device. For some odd reason it's not allowing the new 17 move data and transfer to the other 17. We attempted for 4 hours and the phone would just go in a loop and stop connecting to the other device when it was time to connect and transfer. After spending an entire day at the retail store they said the only other option would be to buy a cloud storage large enough to backup everything "over 200 G's of data," then use the backup on the cloud to transfer everything over. The issue is the 200G is going to take over a week of sync to backup all the files. I have been waiting 16 hours and the backup is done but the photos and videos will is only at 1% out of the 200G. Is there a better solution to this because at this point it seems like this is a very poor way to execute a simple phone data and transfer from an other device.

I also think it's pointless if I have to upload all the data back only the phone taking the same length of time.

I did the 13 Pro Max to the 17 Pro Max myself and it was seamless. I don't understand why the 17 to 17 would be such a headache.

Does any one have a better solution to this long waiting process?

Additionally Best Buy said I only have a few more days till my return policy has ended. Why am I the only who is responsible for an issue with a defective product they sold? Also there are no phones available at the moment because it's out of stock in the entire USA and everyone is on a waiting list for iPhone 17 Pro Max's.

[Re-Titled by Moderator]

Original Title: Data & Transfer Issues