Are you still in a contract? Personally I only do 1 year deals so that I can use that as leverage every year. One season I did cancel with dtv completely but as expected they called two days later with a ton of stuff offered to get me back. Admittedly I pay a ton every month so I could be on their sucker list.
If you argue well enough they will usually come up with free Sunday ticket plus other discounts and a visa gift card.
Good luck guys Just keep trying and you should get what you want.