Actually pretty sure the way Comcast operates is they give deals to new customers - not existing customers, it's not loyalty based. It's completely based upon what level of package you are currently at, and the future prospect of making money off you.
So say you have Internet+TV+Phone..That means you are already an existing customer at a high level, so you only qualify for the good deals on even higher level packages. Whereas if you only had Internet, you'd qualify for a good deal on an internet+tv bundle. I think the max you can get if you're trying to stay with the same package is that original bundle price (before the price gets raised after a yr - but this extends your contract another year)...
So say you have Internet+TV but want a new offer they have for that same bundle, you literally don't qualify for it because you're an existing customer with that bundle already. So what you would need to do is literally cancel TV so you only have internet. Then you would now qualify for the best prices on the Internet+TV package because you are a new customer at that level. Technically you aren't allowed to sign back up for like a month or two or whatever, but are their sales reps going to adhere to that, when adding you back makes their sales numbers look better? Probably not.
And I don't think any amount of threatening to cancel will change that, because when their reps are on their computers looking at their account, their system tells them what the best deals you qualify for, and you only qualify for the best deals if you are a new customer or upgrading to a higher level package. That's just how comcast works as far as I know...
