Basically he cheated you with false promises though you don't have substantial evidence to prove the acts of cheating which is reported to have taken place 12 years ago.
It may not be possible to recover your money especially if was not the owner of the property.
You can lodge a criminal complaint against him on the basis of documentary evidences you may acquire from him
Alternately you can accept the offer he makes now and then plan to recover balance amount through some source.