Cancelled property deal after signing MOU and taken token amount

I signed an MoU with the buyer to sell my flat and received the token amount. the MoU was notarized. 3 days later, due to certain circumstances, I do not want to sell my flat. I conveyed my intention to the buyer and the brokers. Brokers are now threatening a legal case, unless they are paid their brokerage. Buyer is refusing to take back his token amount, insisting that the deal has to go through, or compensate by paying double token amount. There was no provision on the MoU, regarding any financial penalties to any party in case the deal gets cancelled. Am I legally bound by the MoU to sell?