project work not started, builder is not giving money back

I have invested in one project in khalapur taluka district raighar, Maharashtra in July 2014. I have paid 20% of total cost of flat to builder in July 2014. But project work not started yet. Builder is saying that he is still waiting for approval from Cidco for CC. when I ask him to cancel my booking, since I can't wait more now and refund my money back. he is saying that he will deduct 30 percent as cancellation charge and give to me. Also he require more six month to arrange that amount. He is not giving that same in writing also. what to do now. I have given that amount through online transaction and I have original allotment letter.