I have a freehold sales agreement with a developer in Ajman, one of the conditions in the agreement says the buyer has the right to cancel the purchase at any point, but will be refunded with 50% of total paid installments only. When I wanted to cancel my purchase they refused to refund the 50% and said the market conditions are bad at the moment.
If the contract provides that the Seller was supposed to refund 50% of the purchase price if you terminate the contract you may initiate legal action against the buyer for recovery of the amount if they fail to honor this term.
However, we will need to review the full sale and purchase agreement to check if the Seller may refuse such payment based on any reason. Therefore we recommend that you consult with a lawyer along with your contract.