Type up a document with exactly what happened and when. Get your facts straight as best as possible before meeting with the attorney. Provide any evidence you have to support your claim, such as emails, phone records, witnesses.
Sounds like you have quite a mess on your hands but unfortunately you're asking a question on a panel filled with real estate agents like myself. We are not attorneys and can't give you any legal advice. This is a great forum for people looking for answers for questions like "how long do I have to wait when I buy a short sale?" Your question and situation is so much more complicated than something like that. The smartest thing you can do at this point would be to consult a real estate attorney. Make sure you are speaking with an attorney who specializes in real estate. Typically the consultation is free and they will explain to you all of your rights. Avoid the speculation and assumptions that come along with this situation and get the facts.
Best of luck,