Unauthorized charges

I transferred my wifi account on January 2024 from my name to my roommate, i did this my visiting Xfinity store in person. The store person has closed the account instead of transfer and i was charged early termination fee and service fees for Feb and March 2024 which i never used and this charges are given in March 2024 without any communication and there is no notification from xfinity of these Charges. Now in July 2025 I got a notice from collections that i havent paid a bill from Comcast and they dropped by Credit score like crazy. Now its been 2 weeks (14 days) since am interacting with Xfinity live chat almost connected with 30-50 agents may be and this is going on daily basis, every agent raised a customer support ticket which am not sure where they went all i receive is ticket closed, and God knows the resolution what they did. Unfortunately, this platform does not have any customer support email or when i visited store they just told we cannot do anything contact supoort. Every agent agreed its an unauthorized charge and you should not be responsible. Here I am not sure what to do, rather this mental anxiety of impacting credit score for something am never liable should i pay this? or is there a way this worst Xfinity support will address?