Look, I hate Comcast as much as the next guy, but they appear to have competition in your area, even if the competitive product isn't as good. You have a choice, but refuse to exercise it.

The reason they can get away with this is because, like most other people, you won't cancel your service over it. Don't get me wrong, I'm not judging, and I would be paying Comcast too if they would let me, but it really doesn't seem they they are abusing a monopoly in this case.