Sent my “ trade in” phone and never got credit!!

In September 2024, I signed up as a new costumer with xfinity. I got the “trade in” deal and was supposed to see it applied in October bill. I made sure the phone was delivered visa USPS and called xfinity and they confirmed it was indeed delivered and processing. I have called every week since October and went to the store multiple times to just be told that I have to wait until the next bill. I am tired of running around in a circle for months and always being lied to and deceived. I have recorded every phone call and conversation with the staff at the xfinity store so I have all evidence showing they are at fault. I was promised a service and never gotten it and lost a working phone and lost money paying for a new one. I am going to file a complaint with BBB and small claims court now. NEVER DO THE TRADE IN PROMOTION WITH XFINITY!!!