Xfinity Support

Good afternoon I need help taking care of my past account. I had service with Xfinity in January 2024 until January 2025 when I moved to a location where the service was not provided. So the problem I was having was that I never received a physical or email regarding my unpaid balance for the partial month I had service. Due to me never paying that balance it was sent to collections and now there is a derogatory mark on my credit score that dropped my credit by 50 points. I have no problem paying the remaining balance but I need a letter stating that the derogatory mark will be removed from my credit. I spoke to Chavandhn yesterday and he said that I would have to pay the balance and he could give me a confirmation number and the mark would fall off after 3 months but that's not getting the mark removed its just saying my credit would have to be built up again with the mark still being there. I've never had a problem with Xfinity til now and I just want to get this resolved.