I'm in the same situation - recevied 1-3 calls a day for the past two-ish weeks, up to as late as 8 p.m. MST. Never anyone on the line, never a message. When I return the call, the message says Comcast is closed and to call back during normal business hours, even though I'm calling during their 'open' hours. Very frustrating. Comcast knows nothing about the number so I'm not able to figure out how to stop the calls.
Caller with strong Hispanic accent alleges that he's from Comcast. Inbound call to my residence, after 8:00 p.m. Pacific time. Didn't listen to any of the sales pitch. Hung up on this POS.