TMobile Trade-in Offers Issue

I am going through this exact same thing, Feb i received an email about  IPHONE ON US, I traded in my 2 phones   magically one was not set up correctly so I did not get the promo even though I have been calling and trying to get it fixed! one rep tells me no problem I will have it fixed tomorrow and call you back   never get called back  Then I call the next rep tells me nothing they can do and wants me to return my new phones yet they do not want to give back my old phones, or refund that sales tax i paid them! … so I would be out a freaking ton of money cause then I have no phones to trade towards better ones and out sales tax again!   Freaking MAD and they will not do crap!