I had a 2 br booked at GFV last year. On the day of my arrival, while we were still driving, Disney called and asked if we would be willing to stay at a 2 br suite with concierge service included. They said the main difference would be that we would not have a kitchen. We accepted and were wowed with the suite, and really appreciated the lounge access. There were 7 of us so it saved a lot of money on food. I never asked why our original room was not available.
I hope you receive a better solution than what they have offered so far. The grand villas are amazing and I would not want to miss out on them.