Trouble with Xfinity Mobile and need help

Sometimes I have questions about our Xfinity Mobile account and it is quicker to just go through chat rather than try to call in. Unfortunately, more often than not, I do not receive correct information from chat and it ends up causing more problems. In my case, an $1100 problem. Chat agents told me to do one thing when I ported my phone number out and then I finally spoke to a guy today who told me things completely opposite of what chat was telling me. I have all the saved chats where the agents gave me incorrect information, that have the date and time on them. Now, today I have spoken to a phone agent and they have supposedly opened a case to investigate what to do about my situation. My issue is, how do so many chat agents get information incorrect and relay it to customers? The guy I talked to today on the phone tried to tell me I will most likely be responsible for the $1100, and that just doesn’t sit right with me, when I was given misinformation so many times and I ended up being the one to call in to quadruple verify what the chat agents were saying! I don’t know if I should file a BBB complaint or an FCC complaint or what! Is there an email address to the office of the president or protocol to file a formal complaint?