Allotted flat sold out to another customer

I had a sale agreement with the builder on ₹100.0 stamp paper. On this basis a loan was made to me by bank. Builder had to get balance payment from the bank. I had already paid the builder more than 45% on my account. Builder wrote to bank in 8/18 that flat is 100%ready transfer to my account the loan sanctioned. I informed the bank that my flats not 100% ready, please stop payment to builder. Then, builder wrote a letter to me in 9/18 asking for the payment and get registered, otherwise your allotment will be cancelled deposited money will be forfeited and interest will be charged. There is no cancellation and interest clause in sale agreement. I approach the builder, requested for the completion of the property remaining work like installation of windows etc. Then builder told me that the allocated flat no in your name is being sold to another customer. Then I wrote the complaint and sent it to the builder by registered latter requesting for the completion of the flat. All the three letters were returned to me unreceived. Then I approached honourable High Court requesting the completion directions to builder throughout the Allahabad development authority. ADA told the court that project completion will be 10/2019 as per RERA filing by the builder , hence builder cannot be made to complete earlier than the 10/2019. A copy of the writ petition was also sent to the builder as builder was also a party. Builder received the high court copy of the writ petition. High Court also gave me a copy to handover the same to the builder by hand. But builder had not received the copy of the court letter by me. Finally high court ordered to file a complaint against the builder in RERA Court. Builder has so far not informed of the cancellation of the sale agreement, nor refund of the deposit already paid by me. Can UP RERA court cancel the registration of the allocated flat sold out to another customer by the builder. I am interested in the possession of the property not compensation