The account was wrongfully sent to collections, despite repeated assurances that the bill would be adjusted

Dear Xfinity Mobile Support,
I am writing to formally dispute a billing issue that has caused me significant distress and financial harm. As a long-standing and loyal Xfinity customer using both your Internet and Mobile services, I was shocked to learn that my mobile bill was wrongfully sent to collections—especially under the circumstances.
Earlier this year, I had to travel abroad to care for my terminally ill mother, who sadly passed away during that time. While on this difficult trip, I was receiving important incoming calls intended for my Google Voice number. However, to my surprise, Xfinity Mobile routed these calls through its own international network, and I was charged approximately $1 per minute, plus an additional 30% in fees, totaling over $3,000.
At no point was I disconnected from service, nor did I receive sufficient alerts regarding the billing issue. It was only after returning to the U.S. and settling my mother’s affairs that I discovered the bill had not only accrued to an unreasonable amount but had also been sent to collections.
Upon learning this, I immediately contacted Xfinity Mobile support. Multiple representatives acknowledged that a technical issue had caused the incoming calls to be incorrectly billed, and I was assured that a revised, corrected invoice would be sent within a few days. Unfortunately, this never happened.
After four follow-up calls—each time being told the matter would be resolved—I visited an Xfinity store in person. The store manager, Patrick, reviewed the notes in the Xfinity system and confirmed that support agents had agreed there was an error. He even attempted to contact the collection agency on my behalf, but the number he was provided did not accept incoming calls.
I am deeply disappointed that after all this, no resolution has been reached. Not only was I wrongfully charged, but the failure to address the issue in a timely and professional manner has now caused damage to my credit profile. This has compounded what was already one of the most difficult periods of my life.
Unless this matter is resolved immediately—with the unjust charges removed and the account cleared from collections—I will have no choice but to publicly share my experience across platforms including Reddit, Facebook, X, and other consumer forums to inform others about how Xfinity Mobile handles customer billing disputes, even with long-term, loyal customers.
I sincerely hope it does not come to that. I urge you to escalate this matter internally, correct the billing error, and have the collections action reversed immediately.
Please respond as soon as possible. I am available at [your phone number] or [your email address] to discuss this further.
Sincerely,
[Edited: "Personal Information"]