Phone replaced under manufacture warranty

Hola

I wanted to know if there was an email I can send to someone in the corporate office so I can communicate an issue that I recently had. I purchased last June 2021 a brand new S21 plus 5g and 10 months into the use of the phone the screen went completely black and come to find out it was not repairable and I was told at a T mobile store to contact Samsung for the warranty replacement. When I called the Samsung warranty dept. They (Samsung) said they would replace the phone and not only that, for the inconvenience, they were going to upgrade me to a new S22. I accepted the offer but to my surprise the rep for Samsung said I would have to pay for this to take place. Mind you at this point I am confused as to why I would have to pay out of pocket since this is under 1yr warranty. Come to find out later down the road the rep put me down as if I was calling to do an upgrade. He sold me the idea so he can get the sale fro me. I am so disgusted with Samsung and when I received the new S22 it was much smaller than my S21 plus cause he sold me the S22 regular. Now not only am I not satisfied with my new S22 phone I am stuck PAYING for my monthly installment payment for the S21 Plus I NO longer have. I reached out to T mobile support to see if they can help me cancel the monthly payment I was making for a phone that broke just under the 1st yr. No one seems to be able to help and I would like to notify T mobile corporate. Can some one help me with an email? I really need this resolved ASAP!!