Cheated during trade in process

In September 2025, I asked my carrier (Xfinity Mobile Service) about the trade-in process. The agent informed me that I was eligible for a promotion, which could be applied to my trade-in. I was using a Galaxy S24 Ultra at the time, and I still had a few payments to finish.

The agent then explained the promotion deal to me. I wanted a Galaxy Z Fold 7, which would cost $76.66 a month, and I would get $34.58 in credits when I traded in my Galaxy S24 Ultra. My device's monthly payment will therefore be $76.66-$34.58=$42.08.

We successfully finished the order, and I agree.

It has been six months, with numerous back-and-forth exchanges and no conclusion. They haven't applied the credit, which has greatly disappointed and irritated me. My Galaxy S24 Ultra has arrived, but they are still charging me for it, and I am paying the standard price for the Galaxy Z Fold 7. They informed me that I was not eligible for the promotion and that I would not receive credit for it. I feel that keeping my device and charging me for it is unfair. Despite their email stating that I would receive my $830 credit in the upcoming cycle bill back in October, nothing has happened.