customer service email, I tired on waiting in chat and calls

HI I cancelled my service back in August 2023, moved out of the country and Xfinity charge me ~ $140 for no reason, now they send the "due amount" to a collector which I don't know if that is a scam. Sadly the cancellation process did not send any email and when Xfinity send me communication of due amount there is not way to communicate back in email. I can not afford 1hr of my time in a call with multiple people.

I need customer service email to have all communication well documented.

I need your response ASAP