picture scrambling

I am beyond frustrated right now with the disruption in my cable service.  For the past week I have had several (not all) channels having a scrambled/pixelated picture that progressively gets worse as I continue watching the channel, with it eventually being unwatchable.  I have tried all of the troubleshooting, have contacted via live chat, and made a phone call to an agent that was of absolutely no help!  Today many of my regularly watched channels are completely blank.  I am quite disappointed that there is not a better way to communicate with someone at Comcast that can actually help me.  The agent I spoke with was first of all very difficult to understand, and secondly talked in circles, never truly answering my question or addressing my actual issue.  Please connect me to someone who can help!  I shouldn't be paying all this money to have such poor service!