A tip I got on here was to make sure you call 1-2 days before your arrival date. Because they generally do the room assignments 1 to 2 days prior.
We had requested the 101 Dalmations building (a few times actually) When I called 2 days before, they said our rooms had been assigned, but we were in the Toy Story section. I asked them to please put that request in again, and asked if there was any way they could just change it for me. They said they would put the request in. I called the next day, which was one day before our arrival and asked what building we were in, and it was Dalmations! When we arrived, we were indeed in Dalmations, the best room, bottom level, right closest to the food court. It was an awesome location (though a bit noisy).
So it pays to be persistent!
Good luck!