What else did you expect ?

There must be a force majeur clause in the contract. A military coup is considered force majeur. Then again, that would have given the buyer a year or maybe two leeway, not 3....

Answer is ........Keep away from developers, especially farang with a Dutch name !

Developers selling land that must be build upon within a certain time are common all over Thailand.

Empty plots ruin a development.

Empty plots push up the expenses for all the other householders.

Large numbers of empty plots can drive the management company into bankruptcy.

They still have to pay the security, mooban employees, water pumping and sewage equipment and you haven't contributed your share, because you haven't built a house and aren't living there.