Since your contract is nearly up, I would encourage you to start looking, online at least, for other options. Your agent should send an email to the listing agent telling them that unless the bank approves soon, you will be moving on. The bank may not care, but if somehow someone there does, it might help.
Losing paperwork is one of the most common reasons short sales take so long and often fail to close. I know from many personal experiences that I have successfully faxed in all that was requested. I've followed up within 48 hours and had the bank confirm my fax was received and it was complete, only to have time go by with no news and finally have someone at the lender tells me forms were missing. It's a very frustrating situation.
Regardless of the reason or whoâ€™s to blame, start working on two tracks. Tell the listing agent your done when this contract expires and start examining your other options.