complaint department

I need to make a complaint about canceling internet service at my home. I cancelled the service through a live person (and that's the only time I was able to talk to someone and not a machine). Now after cancelling service Xfinity is now charging me 183.00 for late charges and for being in an enrollment program for 12 months. When I cancelled, I specifically asked if I would incur any additional charges for cancelling, I was told "no" and all I needed to do at this point is turn in all equipment, I did. However, I'm still being charged, I do not have money to throw down a rat's hole. Someone please help.