File complaint against builder before consumer forum or RERA and seek orders to direct builder to refund your money with interest within stipulated period 

also claim litigation costs and compensation for mental torture undergone by you 

You have not mentioned that if you had taken any steps to recover your money if you felt the delay is inordinate.

Well, you can issue a legal demand notice based on his own statement that he will return the booking amount with interest.

Failing to comply with the demands made or if he is not responding to your legal notice you can file a money recovery suit or can make a complaint before the RERA or you can approach consumer court with your complaint seeking to redress your grievances 

Under RERA if the if the project is not completed within stipulated time, the builder is liable to refund the advance with 10 per cent interest on refund. You can file a complaint in District Consumer Commission under new Consumer Protection Act, 2019 for refund of advance as it is clear case of deficiency of service. District Consumer Commission is more powerful than RERA Authority as it has power to order arrest of respondent. You can also file criminal complaint against him for cheating. File the case in the Court of Magistrate as police will hesitate to take complaint. Court will order police to register FIR,  investigate, produce accused in court and file charge sheet. After trial Court will punish the accused. Punishment for cheating is jail up to seven  years. Once summons is served on him he will come for settlement, the offence of cheating is compoundable, that is it can be compromised between complaint and accused. You can collect you money and compromise the offence.

1) You make builder's complaint on RERA site and in online Consumer forum.

1. Send a legal notice to the Builder to recover your invested money with interest.

2.  Complain to RERA, Karnataka about the misdeeds of the Builder and urge RERA to intervene in the matter to your advantage.

Dear client I am sorry to hear that but in this case you may ask for the refund of money from the developer peacefully or you can approach RERA for the same. 

You can file a complaint to rera Or consumer court for the same

- As per the RERA Act, if the builder is delaying in construction & delay in possession, then the builder will have to pay 10% interest on the value of the property for delayed possession of flats.

- Hence, if builder fails to delivers the possession of the flat to you on time, then you can cancel the agreement due to his fault and you are liable to get full refund of paid amount with 10 percent interest. 

- Further, if you get the possession of the said flat lately, then also you can claim 10% compensation from the builder. 

- Since, the said builder has already cancel the project and no construction work is started , then he is bound to refund the entire amount paid by you with 10% interest from the date of receiving the said amount. 

- You can send al legal notice to claim the refund , and if no response then file a compliant before the Consumer forum against the builder , and herein you can also claim compensation for the mental agony due to delay in handing over the possession of the flat. 

Lodge a written complaint with the State RERA authority attaching copies of all relevant documents. Issue a legal notice through a competent lawyer demanding refund with interest, and on default, approach the consumer forum for redress, in consultation with your lawyer.

File a petition under RERA, you are entitled to refund of money plus interest of the project.

Send a legal notice to builder. He may pay at that stage only.

If he doesnt, then file petition under RERA