Best Buy doesn't stock the T-Mobile version of the iPhone due to specific carrier agreements and retail strategies

The 16 pro max I got from Best Buy was sold to me as Verizon phone online but turns out it’s AT&T carrier locked. Best Buy associates aren’t able to unlock the phone and want to charge me $45 restocking fee for their screw up if I want to return the AT&T phone they sold me. The only alternative is to wait 90 days or something with an AT&T plan and a new phone number that I never wanted before AT&T can unlock the phone. Trying to do this online from AT&Ts site doesn’t work. I paid off the phone outright, as a Verizon phone with no phone plan from Best Buy online, and did in store pickup. what I received was not what I paid for. The in store pickup associate took awhile before they released the phone to me, and after another associate came they entered the SIM information in their system that was printed on a sticker attached to the iPhone box. During initial setup, I signed into my Apple ID and it said my Verizon number was not transferable. Btw, Best Buy asks if the package is opened. How else would I have known you sold me the wrong phone, until I open it? The box and stickers aren’t labeled as AT&T anywhere. The order receipt in app says it’s activated with Verizon / bring your own number. I used to use physical SIM cards, but that’s not available on newer iPhones that just has eSIM. Not like that would help anyway since the phone was carrier locked to AT&T, and Best Buy doesn’t unlock the phone if you pay outright apparently. Don’t make the mistake of clicking activate eSIM during initial setup. Next thing you know, you’re now an AT&T customer even if you’ve never had an account. I have no clue what plan I’m on or how they intend on billing me since I gave AT&T no information. I’ve spent an unreasonable amount of time trying to get this resolved and will have to eat the restocking fee and dispute the charge with my bank. What a mess!!!