When you talked to Disney did you ask them to check the availability of your pin. If it's marathon weekend, there may have NEVER been any availability.
Also, the fact that you have a specific room booked decreases the chances of availability of that specific room type with any discount.
Disney releases all discounts based on the number of empty rooms when they release the discount. Then they block off rooms for each discount that they offer.
The lower the number of a certain room type to begin with decreases the chances of an offer being released.
Ex. There's only 1 Presidential Suite at the Wilderness Lodge, even though it's really expensive, people will pay the money to stay there.
The popularity of a room type decreases the chances even more.
Ex. The Family Suites at AS-Music hardly ever are available at a discount, because people they're hard to get even before discounts are released.
Basically, if you like a room because it's different, chances are other people do as well.
Even when people cancel rooms with or without discounts, those room don't become available with a discount, they become available at Rack Rate, so the longer a discount is available the less of a chance that it will be able to be applied at all.