No availability recourse? Sheraton Broadway Plantation

I own a 2br lockoff, I split the units this year, booked large side for earlier in the year.

I called today, trying to make a reservation for the smaller 1br side, and was told there is NOTHING available for any Friday, Saturday or Sunday for the rest of the year. How can that be?

I asked how I can use the ownership piece, and was told I could trade it into Interval. No I can't, Internval will never have a unit to sell to someone else.

Never had this happen, I've missed out because I waited to long to get a week I wanted but never been completely shut out.

Any suggestions? I guess my next call is to resort GM to confirm