If you hit that many bad dates, just say to the agent "I have tried 7 dates from two airports to be flexible. Could you request an additional seat be made available for me on any of those days?" So long as you have worked to be flexible, then they will oblige you with the same.
I always have an easy time redeeming, but I believe the Wendy's promotion has flooded AirTran's 10% available seat capacity for free tickets.