Who can I talk to about this?

I moved to a new address in June of this year and moved my 2GB internet plan with Xfinity to this new address. From the beginning the internet was much slower than my old place, which was odd because I was in a 5th floor condo and had moved to a place where everything was ground level. In October of 2024 I started noticing that the internet would stop working. I was able to get going again by unplugging the modem and restarting the system.  Eventually it stopped working all together. I thought it was my modem so I set up my old one again and the internet was still not working. I scheduled a technician to come out and it was discovered that the issue was faulty Xfinity equipment in the room where all the coaxial lines go to units. The technician informed me that I had not been getting what I was paying for the entire time due to old equipment that was not able to handle the faster internet speed and that equipment had totally failed. This was a big enough issue that another tech was sent out that day to replace all the faulty equipment. Turns out that many people in the building had this old gear and did not realize it so they all got upgraded that day too. I reached out to Xfinity after this was resolved to get prorated for the months I had been paying for the service with faulty equipment. I was told that it would be handled and that I would see a refund or some kind of credit applied to my account while on the phone with an agent.  I have not heard anything back from them and they have cancelled my ticket without reaching out to me.  I feel they need to credit me for this expensive service that they were not providing this whole time. This was not a "speeds may very" situation, this was faulty equipment on Xfinity's part.  Once the issue with the internet was resolved there was a significant boost in the speed which means that I was not getting what I was paying for the entire time I have been here. Getting someone on the phone to resolve this is next to impossible, when I do get someone I am told this will be taken care of in my favor then the ticket is closed without hearing from anyone.