Phone upgrade issue

Ok I have ran into a problem that is about to cause me to go to another provider even if it cost me more out of principle. This is what happened I was talking to a rep about mt auto pay and changing my account and somehow she brought up promotions and trading in my phone. I explained that I have a old grandfathered plan and have worked hard to keep it paying case for all of my phones so to keep it. On top of it that last time they had a promo I could used which was trade a eligible phone at Apple and show proof of trade and that I was staying with t mobile that I would receive a $200 visa debt card in the mail, and just to add I had used this same program successfully twice before but for some reason the last time I never received it and after at least 10 hours on the phone with them being promised every time that it would be fixed it never was. I gave up out of frustration but I at least still had a really good plan. She tells me well since that happened and you had been with us for many years she would get me the trade in promo where I trade in my I phones and get to upgrade to the new 16 pro at no cost after bill credits while keeping my plan the same. She would just need to have her manager override it in three days and I would have my new I phone 16 pros on the way. ( I had a paid off 14 pro and 13 I was trading) I said that would be amazing and it would be like a early Christmas present for me and my spouse (The only Christmas present we would get because its been a hard year) I was so excited and told my spouse and everything . Now she never calls me back on the 12th as promised to set up and I've ben told three times now I would need to wait 48 hours for them to escalate this but basically told me no I could not get that even if I was told it. So not even the reps that escalate it tell me they will call me back and never do like promised so I need to call. Today a manager tells me she is going to handle it by getting the first rep in trouble and I still could not have what was promised. So I say so now you are just making me feel worse for complaining getting someone in trouble and you still are telling me I will not get what is promised. She says yes and I say I don't want to get her in trouble and you just made the situation even worse because I am not only not getting what was promised but you are telling me how you are going to get this rep in trouble for me, when I don't want that. Now she says she needs a week to see if she can do anything. I tell her that this is now the 3rd call back for the same reason and I need to call back every time because I don't get called back as promised and it sounds like I am not getting it anyway based on what you are telling me  . I've never been so unhappy and am trying to find somewhere else to go so I can get this present I told me spouse about and out of principle. I'm even sad because I like t mobile and all I did was get someone in trouble with nothing to show