Xfinity Trade In issues

As many have stated after months of trying to get what we were promised, credits for our trade ins. I have not received my credits. The stories are all the same, received, under review, don’t worry you will receive your credits. I was told that it would show up on my 11/6-12/5 billing. Nothing on Xfinity app. Last chat:

nullAgent (09:33 pm): However rest be  assured as I am check in your Current cycleBilling cycle: Nov 6 - Dec 5 the credit for the amount is added and you get the credit of your trade in promotion successfully from the upcoming billing cycles. As well as you get the whole credit which is not added in your previous billing cycle. 

Agent (09:34 pm): And you will receive the credit amount which is promised with you $20.83/mo for 24 months