I'm assuming this is an REO property. In purchasing an REO you typically sign an additional bank addendum that demands much more aggressive execution and commitment from the buyer. Almost every bank addendum I've seen has a time lapse removal of contingency clause... this means that the buyer does not remove contingencies (loan contingency, appraisal contingency, inspection... etc.) in writing. Rather, once a certain amount of time lapses in escrow without the buyer backing out (typically 5-10 days) contingencies are assumed and effectively removed. Read your bank addendum carefully. I've found that the banks are very aggressive in keeping deposits.
Good luck in gaining resolution in the matter.