Cheating by builder

Paid booking amount to builder 3 years back with a confirmation from the builder that the OC is expected to be received in 3 months. As the building structure was fully ready with only lift/ fire installations left and some other minor works were pending we relied on builder promise 2. New call was made for additional funding Property is fully ready - NoCs from Fire Department were awaited in few weeks then immediately OC will be released and once OC is recd, registration formalities will be completed. This looked promising & already been waiting so we paid as and when the demand was made almost 50% of the amount is paid. 2. Since past one year - we are just listiening to the excuses one after another - State/ Center Elections, Heavy Rains, Death in Family of developer, death in family of Manager, Personal Matters, finally even COVID 3. Since unlock activity has started all over the country , we started chasing the Builder from last month - to have a meeting and to complete registration of property in our name but builder kept postponing the meeting and now since this week not even answering the calls. Recently we learned they have Shifted their office and even place of residence. Don't know how to track Property is not RERA registered. Please help