Would need a LOT more information about the circumstances. There are many ways to work with or stall a lender. In many cases you can stop them in their tracks but sometimes you dont want an adversarial relationship. You need to speak to an asset preservationist who knows debt management. I know the number one man in Oregon for this. Drop an email and I'll give you his info. Otherwise---do not take advise from just real estate people here...as others said---contact a lawyer. DO NOT SPEAK to your lender until you get advice.
Regarding short sales and experts, everyone is claiming to be a short sale expertand some have taken a few courses. Though its not rocket science, it does take experience and there is only so much a 'short sales expert' can do anyway. (This isnt pointed at Linda, below, Im just saying in general) Thye public doesnt know how to choose a short sale agent or expert. The person I referenced above is used by many large real estate offices who wont let their agents touch a short sale without his input. Again, contact me for his info. I get NOTHING for that, by the way. GARBLOOEY AT GMAIL DOT COM