Fraud islamabad

Salaam
Recently tried to purchase a commercial plot
I am an overseas pakistani
I was told the plot had planning approval from islamabad cda
Agreed to purchase on that basis and gave cheque as deposit
Next day find out planning approval had been refused prior
Seller says he was not aware
So i cancelled cheque given as deposit
Seller is now threatening legal action for cancelling cheque
What are the legal implications for buyer and seller?