Money Owed On Old Account During Transfer

Moved from Illinois to Michigan back in October of 2024 and still dealing with billing issues.

I've spent more hours on and off the phone dealing with Xfinity than it took me to pack and move a 3 bedroom house across 2 states. Still dealing with these issues 7 months later.... Xfinity told me that we needed to create another account to move states and its caused nothing but issues. Bills were being applied to my old account and surcharges were being added since their system thought I cancelled my service, even though I only transferred services to a new location and account. It was Xfinity that told me I needed a new account and now I am the one paying for Xfinity's mistake. After, once again, spending hours trying to get ahold of someone versus their Xfinity assistant - describing the situation with over and over and over again with folks from their customer service and finance team - they told me I it was all squared away. However, this was not the case. They credited me only a portion of what was applied and now I'm getting notified by a collection agency for $50 because Xfinity [Edited: "Language"] up and the countless individuals I dealt with had no idea what they were doing. After calling Xfinity once again about the collection agency, I was informed it would be taken care of. I asked for a written document from Xfinity that this would be resolved and I never received one. So here I am writing this post looking to get this fixed. 

Worst experience I've ever had to deal with and doubtful I will ever see resolution here based on my history with xfinity the last 6 months on this issue. I need resolution on this situation ASAP.