How to recover the bana amount from seller and deal is cancelled

The Consideration Price of the Flats have been fixed sat Rs. 45,00,000/- In Words rupees Forty Five Thousand only and as advance an amount of Rs. 3,55,000/- In words three lacs, fifty five thousand have been paid. Out of which Rss. 3,00,000/- have been paid Through Ch. No. 40095 , of Axis bank, Drive in Road Branch has been given on the name of Seller’s son as per his insistence. Rest Rs. 55,000/- have been paid in cash. Which have reached to the Seller or the Lakhi Aapnars. The remaining amount of Rs. 41,45,000/- will have to be paid in full at the time of making Sale Deed .The time period of this Sale Agreement is fixed for one year. We the sellers have given you firm undertaking and assurance that the tile of the property is clear and marketable. And today the sellers have given the original papers and sale document No 4553/2003 and No dues Certificate issued by the L& T Finance dated 28-10-2014 have been given. The Original Share Certificate of the said property have also been handed over today. Now henceforth, when the remaining consideration amount will be paid, you the Buyer will be eligible to make the sale deed in connection with the banakhat. e) In case within the time period of the Banakhat, we the sellers will make the registered sales deed in favour of the Buyer. And if due to any circumstances is not made, you the Buyer will have right to lodge civil suit of specific performance . And if due to any reasons within the abovesaid time frame, you the buyer do not get the registered sale deed made, then the amount of bana is to be returned back and if the sale deed could not be made within specific time frame then for removing such constraints, the time period of the banakhat will be increased with mutual verbal consent of both the parties. The original Bankahat will be with Sureshbhai Panchal and the Xerox copy will be kept by the Pankajbhai Vasudeva. Sir thid deed was made on 20-12-2014. unfortunately party didnt had building usage due to this we didnt got a loan. now we dont want to purchase this property. seller is not returning bana amount to us. its almost 1.5 yrs from the date of bana registration(its a notarised document between us). which is the best way to recover money from the seller.