Problem after problem. I cannot get Help to save my life.

I’ll be detailed as I can. I’ve been dealing with this for about two months now. At the end of October, I decided to get an iPhone so I went into the store and I got a iPhone 15 Max Pro. I wasn’t aware that I could trade my Samsung Fold six in. So I decided to do a return within the 14 days in return the 15 max pro. I called got a representative on the phone explained to them that I wanted to return the 15 Max pro that I just purchased and purchase a 17 Max Pro and use my Samsung Fold six as a trade-in. For some strange reason, the representative thought I wanted to get an exchange and another line. I wasn’t aware of any of this. So a couple days later I get FedEx at my door. I opened it up and there’s two phones in the box. There’s a 15 Max Pro and a 17 Max Pro. I was very confused. So I called and after sitting on hold for about two hours, I finally found out they did an exchange for the 15 and added another line to my account for the 17. That is not what I wanted. So by now the 14 day window to return, the 15 is now gone over and now I have to tell everyone a new number because the 17 was set up correctly with my trade-in. The person that I talk to you on the phone Said to return the 15 as a non-solicited return. I’m not too sure the verbiage on that I might be saying it wrong. So I decided to box up both 15s and return them with the return slip that they provided that I got emailed to me. On another note, I have that promotion for the free mobile line on the 15 that I want it on 17 because I don’t need two phones. Now After two months, I have two phones on my account that they’re saying it’s still in pending order. It’s basically I’m paying for two phones and two services and I can’t get no one to help me every time that I call and sit on hold for hours. Nothing gets done. I don’t understand how hard it is to move a promotion from one line to another and then cancel the original line. I didn’t want a different line. Everything was supposed to be done on one phone. I’m just huge problems and no one can help me.