I realize now that I was too quick to use the word "lied". Some posters have informed me that the Song agent must have had my flight appear on her screen as "sold out", whether it truly was or not. It was a knee-jerk reaction on my part to flip out after I spoke to her.She might not have been lying.
Now that my flight is back and accepting ressies, there are only 2 possibilities that I can think of: 1) a load of people cancelled their tickets at about the same time 2) the plane was never truly sold out
Anyway, after I calmed down about the possibility of my flight being cancelled, I thought it may be a good thing after all. I booked a 5 PM flight, but have been wishing I booked an earlier flight, and just miss work/school that day. So then I thought that if my flight gets cancelled, they'll put my family and I on an earlier flight, and we'd have those extra hours at WDW. If I change the flight myself, I have to pay Song $25 per person, plus the price difference from when I booked to what it is now. I booked when it was something like $75, and now it's $349, so there was no way I was doing that. If Song changes your time, it's free.