This may have been answered before but I can't find anything: a flight I've been looking at in July has been $450 round trip with the ability to book with 16 credits. Today I check and the flight is still $450 but can only use credits towards business class. Once the coach award seats disappear, are they gone for good or do some occasionally show up? I've seen it happen where you can't book awards when the full fare goes up but that's not the case here.

If it helps, this is for the nonstop service MKE-CUN that runs only on Saturdays. Would calling Airtran yield any different results?