How to escalate or get a sales rep?

Any ideas how to escalate a problem with Comcast, or get a sales rep?

Our Comcast Internet used to be rock solid, but last few months not so much.  When I call tech support all they say is "It's your fault, you have too many devices" (I have data that indicates a new problem on their end).  They won't give me a sales rep, invaluable with other companies when excalation is necessary.  We're pursuing alternative service, but that's not a short term solution.