Builder is reluctant to refund the advance.

I don't have agreement signed with builder yet. I've made a total payment of rupees 150,000/- the builder and I have the receipts and proof(cheque and Bank Transfers). The project was suppose to start during first week of Jan 2016 and nothing has happened yet. This builder is in from Bangalore, this is the city where I'm currently put up. While making payment, I was promised that entire amount would be refunded... if I'm not interested in the project before agreement. I have waited for more than six months for now and I don't have any interest in the project and I need my advances made back. I first approached the builder on April 2016, requesting for cancellation of the booking and refund the amount. He has been giving blame excuses and asking for more time. I have proof of communication and voice recording with me starting from June 2016. Please suggest, how should I proceed further and what are the risk and investment involved. I look forward to your reply. I would like to know the cost involved to issue a legal notice and the next steps. please suggest.