Apple ordered phone returned to Tmobile (TMobile stole my phone)

On February 1, 2024 I purchased an Iphone 15 Pro Max from Apple on the T-Mobile network.  The new phone was priced at $1199 and Apple was giving a trade-in credit of $610 for my wife’s Iphone 14 Pro Max.  The difference of $589 to be financed by T-Mobile with bill credits.

My wife decided to wait for the Iphone 16 so I started the return process to return the 15 Pro Max unopened.  By error instead of calling Apple first, I called T-Mobile.  I received a return label from T-Mobile even though the phone was not ordered through T-Mobile.

I received confirmation on February 13, 2024 that the Iphone 15 Pro Max was returned to T-Mobile warehouse so my finance agreement with T-Mobile was cancelled. Now that Apple did not receive the trade-in nor the Original Iphone 15 Pro Max, they charged me for the $610plus tax of $646.60. 

I called T-Mobile multiple times and spoke with multiple people.  I was told that T-Mobile cannot return the phone nor give me credit for the balance of the Iphone 15 Pro Max.

Has anyone faced this issue and if so was there a resolution? What do you recommend?