Negative customer impact for Xfinity's error

I received the Storm Ready Wifi service and device in June 2024. The device nor service ever worked. After numerous troubleshooting attempts and a technician visit, I was told Xfinity added the charges but never properly linked the device to my account. The device was not able to be properly linked, and the technicians supervisor sent me a UPS label to return the equipment. They were suppose to call me the next day to get the tracking number. Once they received the tracking, they would fully refund all associated charges and if I decided, a new device could be added properly. IF they called, they left no message, no email, no text, nothing for me to follow up. I completed my part of the agreement by dropping the device off at UPS with the provided label. I have continued to be charged even though I call every month and have been told EVERYTIME it was taking care of. As of August the full device total was charged to me account and remains. More calls, more chats, promises it will be fully refunded, and now my service is at risk for termination. I need help from management in the USA that can fix Comcast/Xfinity's error!