mobile trade-in credit - Escalation

Hello

I am a mobile customer who traded-in my phone for $1100 in credits in a recent promotion. The phone have been received and accepted by Xfinity per the emails i received, but no credit was received.  Support agent just reassure falsely to wait a month before seeing any credit. I had sent two other phones after this first one for which i am receiving credit. 

I am afraid, in addition to not getting my $1100 credit, my trade-in (iphone 14pro) is also lost to xfinity

What is the process to escalate within Xfinity, if there is any way reassure me that i will get the credit.  My next steps would be to complain a the BBB/FTC of this and seek resolution

Thanks