Seller doesn't react / wants to sell himself after DD period

[Seva Kotov]

Hi guys.

I have a signed purchase agreement (land lot) with a notarized affidavit of memorandum which expires end of the month.

The seller does not sign the last paper needed for the title company and doesn't react to our calls and mails.

It seems like he wants to wait until expiration and sell it himself.

Any ideas how I could act in that case?

Thank you!