Which ferry company sold you the tickets? If it was RTFF, that makes sense because they have Saturdays in the current schedule.

I too am waiting the RTFF November schedule to open. I called yesterday and the lady said sometime next month. Just hard to book a flight out of STT when you cannot secure a ride there...I too could be stuck in paradise.
If you see the schedule open please let me know and I will do the same LOL