Novation of Contract/Effect of Cancellation of Contract

I have booked for a flat( 90% completion) for Rs.75 Lakhs and Rs.60 Lakhs was paid upfront. The sale agreement was signed. After 1 month, the builder has demanded for a cost of Rs.90, for which we have not agreed. We have requested the builder to cancel the contract and the builder did the same and we entered in to a new contract with the same builder, after cancelling the first contract. But after 2 months, as things were not moving, we have requested the builder to cancel the new contract. After constant persuasion, the builder cancelled the contract and the cheques were issued in 3 instalments of Rs.20 Lakhs each on Nov 2016, Dec 2016 and Jan 2016 and the same got bounced when the same was presented in the bank. And we have filed a criminal case against him. During last 6 months, we have filed a complaint with RERA regarding our case. The adjudicating officer is not issuing a decision in our favour mentioning that, since the first contract was cancelled by entering into a second contract, RERA cannot give a decision in our favour as the first contract is not existing at the time when RERA was constituted. Whether any Supreme Case decision to upheld our demand to get a decision in our favour from RERA. Please advice/help