Promised Service Credit Not Issued

After considerable difficulty Xfinity finally replaced the exterior service box.  This forum was instrumental in getting it replaced.  The visit and external repair was an Xfinity responsibility that they acknowledged.  But Xfinity then charged me an approximately $100 service charge.  I would like to provide the exact amount and date but both the account section of the site and the Xfinity Assistant keeps saying it's having difficulty accessing my bill and then eventually disconnects.  After I learned about the charge I was able to chat with a live person.  That was several weeks ago.  They assured me that the charge would be deleted and that I would see a credit on my next statement.  Unfortunately Xfinity, perhaps intentionally, provided no way to save or download the chat the way most reputable service providers do.  I attempted to start a chat using Xfinity Assistant, but that will not work because it creates endless loops.  The current projection of my bill clearly indicates that no credit has been posted.  How do I get the credit?