I have several of these numbers from over the years, and earlier this year at least one of them worked when I was making reservations. Last week, I could not get a single one to go through. Disney places these numbers in and out of service as they deem them useful to their needs. I just try them each time I need to call.
What I did last week was wait until I had free nights and week ends on my cell, and gave them a call on it. Same as an 800 number, and no hoping it was in service. I don't think I will fool with an 800 number again, as you can make ressies on the week end just as easily. Hope you get the ressies you are after.