These can be tricky, and of course I can't say for sure without reviewing the actual contract; short sales do take a long time. However, time is of the essence, as always, and the parties need to keep up with extensions. In general, you should get your hand money back when the sellers default.

You would sign a contract release, plus a separate distribution of hand money form (saying it goes to you), and present it to the seller. Hopefully they'll sign, and you'll get your money back. If they don't, you can either wait it out or go to the magistrate. (Unless you didn't waive mediation, in which case they'll send you to mediation first.)

Good luck!