Builder Cheated Fraud on me Twenty Lakhs Rupees sold out apartment to other party the flat assigned

Respected Lawyers I need your valuable advise on the case of builder fraud on selling apartment, on year 2017 both builder and myself agreed on the terms of buying apartment, I paid initial amount of Rs.11 Lakhs (cash), then the builder was demanding more money for which I had further paid 3 lakhs (Two online and 1 lakh cash) on Aug 2019, and then on Dec 2019 Six lakhs rupees. The builder had given an agreement of 14 Lakhs rupees and given receipts of 3 lakhs & 6 lakhs rupees. But demanding more money and the construction of apartments were not started, but then in Nov 2020 he called me and using abusive language and then disappeared, and then Covid-19 etc. I travelled to Chennai by Oct 2022 and called him several times which he didn’t answer back, and I travelled back Hyderabad, again I travelled back in Oct 2023 but surprised to know that he sold out the apartment to other party, and when I went to ask to refund my money 20L he again used abusive language, provoking me and tried to assault on me but I left the place and lodged complaint to Commissioner of police, no update over month then I lodged online complaint to DGP but then got call & I had provided all the supportive dcmts, but police sent summon which he took almost one month to reach, appeared when I travelled back to Hyderabad. The builder reached and provided 3 PDC, each in 3 months of five lakhs and informed police to collect the agreement. I responded to the police that I won’t handover the agreement unless the amounts are credit in my bank account and he should refund the whole amount of 20L, as he agreed to refund only 15L. Kindly give your valuable advice on how to take back my whole amounts and what are the other remedies available. Thanks, and Regards SAM