You have a right to sue the Thai women claiming for the money back.
Please keep in mind that you, as a foreigner, are not allowed to own any piece of land in Thailand unless you invest in Thailand with a substantive amount of money as required by law, and get permission from Thai authority. (You may search for more information regarding this matter in this Website, Article Section.)
Under the present circumstance, the Court will not allow you to own the land, but will allow you to sell the land within a certain period of time. Otherwise, you will be forced to sell the land by public auction, and you will have to pay commission to the Thai authority for doing so.