Samsung/AT&T Changed my plan/phone without my approval.

Been an AT&T Wireless customer since the Cingular days and while on activity duty with USAF. On 1 Feb, I pre-ordered a Samsung Galaxy S23 Ultra (AT&T Version) through the Samsung website (paid full retail price) and my nightmares started. I had a Elite Unlimited plan with HBO Max for a couple years. To my dismay, the a couple days later, the S23 Ultra was activated and my primary number/phone was deactivated. Mind you that the S23 isn't even scheduled to be released until 2/17/2023! Called AT&T (some overseas rep) and told them how can you activate a phone that hasn't even be released yet? And it was done without my specific approval. To make a long story short--they reactivated my phone S21Ultra, and said my HBO Max with Elite Plan would be restored within 24-48 hrs. All was approved and that it would be documented on my file. Go back and find out that my plan was changed to the Starter Plan (even a had already paid for the elite plan Jan 21-Feb 20). The rep said they would give me a credit on my next bill for the inconvenience. It was in reality a prorating of my bill (lied to again). Second call said, no you can't do that and that you can go back. No record that I had even called to report the issue. Now, I'm stuck on the Starter Plan until the 21st, no HBO Max, when I should be on the top-tier plan--and have to wait to find out if my bill is going to be messed up because of these two deceitful responses from overseas AT&T CSRs.  I thinking of filing an FCC/BBB complaint as well.