Short Sales with Bank of America have not gotten easier, if anything they seem to take longer then all others, except Ocwen.

I am a buyers agent on a short sale with Bank of America. When our offer was accepted ( we were the back up) on March 3rd, 2014..That it was an approved short sale. Since that date my buyers have completed all the requested documentation. Bank of America has done three appraisals in the past four months. This property is set for TS on August 1st 2014. The listing agent does not return my calls, the bank won't speak to me. The listing agent has opened escrow and order prelims. and documents from my  buyers, yet no approval from the bank. Do I have any recourse or direction I can go? My buyers are so stressed with the constant "anyday now" response, jumping through hoops for everyone on the listing side, yet no approval from Bank of America.