Ha ha! You're not the only one who has problems with these types of organizations. The problem isn't just Comcast, of course, it's visible in many companies out there that don't require any kind of related higher education to handle technical services correctly. It's no wonder that you'll almost always get the run around when something much more than "the modem's unplugged" is the problem. The only people who really know this stuff are the engineers who designed it or people who are well educated formally in the intricacies; and you ain't going to get them out there dealing with irate customers for $30K plus 10 holidays and 7 sick days a year.
Back in the early 60's when I was a kid, the TV repairman would show up with a briefcase full of tubes and start plugging and chugging them until the problem was fixed. Most of the time he was relying on personal experience because that was all that was required of the comparatively simple technology of the day. If the screen's rolling, it's the vertical hold tube. If it smells like rotten eggs, it's a bad selenium rectifier. It was the same kind of thing when we used to be able to work on our cars ourselves.
Today's not the same. The complexities of computers and their associated hardware and software are simply too far beyond the capabilities of some $20/hour cable guy with a couple of weeks worth of "technical" training at Comcast. Most of the experience he derives from the job merely leads him to a greater understanding of how ill-equipped he is for the task at hand.
Ever talk to one of those technical customer service people on the phone from another country when you're having computer ISP problems or your Garmin 496 is on the fritz? You think some f^&king ghetto snipe from Bumfuct, Egypt whose last job was watering cattle is going to know anything about this stuff other than what the crib sheet in front of them is telling them to say. Half of these people aren't even outside this country, but sound like they might just as well be based on their command of our language.
They probably figure that after awhile we'll get tired of "aksing" questions and just go away.
You isn't alone and it ain't gonna git any better.