Billing Escalation — Complaint [Edit: Personal Information] Unable to Submit Supporting Documentation

Hello Xfinity Support Team,
I’m posting regarding Complaint [Edit: Personal Information], which I’ve been told is currently under back‑office review.
I’m trying to submit supporting documentation (chat transcripts, billing confirmations, and emails) that directly corroborate this complaint, but I’ve been informed there is no email channel to send evidence and that the back‑office team may proceed without reviewing documents.
For clarity, the complaint centers on a misrepresentation of my total monthly billing. In August 2024, I was explicitly told my total out‑of‑pocket cost would be $60 per month. Instead, Xfinity billed:

$60/month for Internet via bank autopay and
$38.68/month for Mobile/iPad via credit card

In March 2026, multiple Xfinity agents confirmed a $1,160 credit was applied to correct this issue and instructed me not to make payment while bills were adjusted. That position has since been reversed, despite prior confirmations that my bills were already being offset by the credit.
I am not trying to open a new dispute. I am simply requesting guidance on how to submit my documentation so it is reviewed under the existing complaint.
Please advise on the proper next step.
Thank you.