Report poor customer service

I just got off the with agent that was so arrogant he laughed at me it's like comcast doesn't need you losing you as customer will not hurt comcast...My is I had a payment arrangement that wasn't honored a check was processed twice for the wrong amount...The agent could cared less about what had happened to my account as well as my payment arrangement...I got so upset and frustrated that I told the agent I am going to turn in there equipment that when he launched at me and I could turn in the equipment if I want to comcast is going still charge me for a extra month alone with the payment that due now...Comcast is a company that's in small cities with no competition that treats it customer poorly...As of today I moving from comcast completely I I was customer who had all services internet, cable, landline phone as well as the cell phone service I am letting it go today the bill is absolutely to high to begin with anyway with old old dated equipment...I have super sick of this ungrateful company and with the treatment I have received and the attitude I positive absolutely nothing will done...After they believe we need them because they surely don't need us] ⁰