No trade-in credit after sending my phone for 3 months

9/30/2024 sent old device 

10/4/2024 shows delivered ono USPS

10/28/2024 reached out to Xfinity, agent confirmed the device is received by Xfinity

12/23/2024 reached out to Xfinty, agent confirmed the device is received and accepted by Xfinity and will receive the credit in the next billing cycle (12/14-1/13)

1/15/2025 no credit on the statement, reached out to Xfinity, "another" ticket is created....

Reached out multiple times asking for the status of the trade-in for trade-in credit of $700, agents confirmed the device is received and accepted, one agent even said if no credit is applied, they can "manually" enter the credit.  However, I reached out again and all I got is "the most I can offer to you is $20 credit...." This is unbelievable. I don't understand how a trade in can take more than 3 months and I still not receive the credit. Customer service cannot even provide a resolution and only creating tickets and say someone will be contacting you, but guess what, never receive the call... I have seen a lot of complain on Xfinity trade-in and was wondering if I will encounter the same...