My strategy to save the deal

We threaten to sue the bank. Once we start the legal process, we will put a lien on the house to block the sale to other buyers.

Even if we lose eventually, the bank will not be able to sell during this time. The law suit can take many years. Once the suit is over, the house will be ruined.
This is going to be a nightmare for the bank.

Does this work? Please advice if you have experience.