iPhone 14 Pro bricked just before and after 26.3 update.

Okay, so my iPhone 14 Pro was experiencing issues, and the battery needed servicing. Battery at 77%. I scheduled an appointment to have the battery service done. The morning of the appointment, I took my phone in, and it locked up on the Apple logo. The service personnel told me a battery replacement would do no good. They instead recommended to plug it into a pc or my Mac and update or restore the phone. I updated the phone to version 26.3 via my Mac mini, and it came back to life for a short period of time, approximately 2 hrs. It locked up again.

This time, when I plugged the iPhone into my Mac mini, the only option was to restore. So I restored. The phone came back to life, but with a caveat. It took approximately 36 hours to be usable again while it restored and downloaded the apps and data from the cloud. After that, the phone was only usable for about three hours at a time, and it would reset with a white screen and blue text stating that it required activation. Then the period of time the phone was usable shortened to 3 minutes. Now the phone is unusable. Now we are stuck on the support.apple.com/iphone/restore screen with the computer plug-in logo. When the phone is plugged into my Mac mini, the phone attempts to restore but fails with:

The iPhone “iPhone” could not be restored. An unknown error occurred (9).

During the process, the progress bar makes it to about 90% before failing.

I have attempted to order a replacement but have been unable to receive a confirmation code to complete the purchases.

I am headed to the At&t store now with a phone that I am afraid won't qualify for a trade in.

If there are any alternatives I would appreciate the help.