The bulider/seller is delaying refund, cancellation was verbal

A property deal was done on 20th Feb, due to non-approval of loan, deal was canceled (mutual ground), and builder said he will refund the whole amount. Till now an amount of Rs.6,81,000 has been paid, Rs.61,000 cash and Rs.6,20,000 in cheque. Only agreement paper work is done till now, that too on a Rs. 100 stamp duty paper and not on Rs.1000, and there is a subclause that if the buyer fails to obey any of the terms it will result into forfeiture of whole amount paid. The sale deed does not have the signatures of the actual buyer but of his blood relative, which the builder said to do since the actual buyer was not present. The builder adviced to cancel the deal since we were unable to get the loan senctioned, and promised to refund the whole amount. The builder now says he won't return the amount utill he sells the property and if he fails to sell the property I will have to buy that property. He is making excuses in refunding the amount.