Contact your State Attorney Generals office with all complaints - no Comcast corporate customer support service exist. This is a simple online form and has been very effective for me.
Took me 3 tech support calls and 3 weeks to get my cable hooked up thanks to tech support's scripted process. Then took 3 attempts to get refund for unused service. Then started being charged for a premium service I never enrolled in, and again took 3 attempts to have service disconnected and money refunded. All this occured over a 6 mos period.
Comcast is incapable of even providing tolerable customer service. Finally I filed a complaint with the Tennessee Attorney General and Comcast was calling me within 5 days.
Monetary Loss: $20.