Make sure to file a complaint with your state attorney general. Cases like these can quickly get their attention and more importantly, companies don't want to be investigated by AGs. Unlike state regulators, companies are less likely to have a pre-existing relationship with them. Since you're talking about telecom and not just internet, it's also worth checking to see if that is regulated by your state PUC/PSC. Don't bother with the better business bureau. A company can have an A rating as long as they respond to you, they don't actually need to fix your issue.
Also file complaints with your city. Comcast relies on licenses from the city to use the poles for their cables. Complaints about bad service tend to get fixed quickly when their franchise agreements are in peril.
