ENDORSMENT/TRANSFER OF UNDER CONSTRUCTION FLAT IN SECOND SALE

I bought an under-construction flat in resale from the first allottee in the year 2014 and cleared all liabilities of the first allottee. The flat was booked by the first allottee in the year 2012 and the first builder Buyer agreement was executed in the year 2012. The builder instead of endorsing/transferring the flat in my name, executed a new Builder Buyer Agreement w.e.f year 2014 with a new possession date. The builder has issued all the money receipts in my name since 2012. The flat possession has yet not been handed over till December 2020. Under what rule can I ask the builder to execute the Builder Buyer Agreement in my name w.e.f the year 2012 instead of the year 2014? Kindly cite relevant judgments/rules.