Cancellation of flat sale

I had booked a flat for Ten Lakhs and the amount was paid by 2 cheques one in the Builder's wife's name and the other in company of the builder. After paying money, i came to know that the builder has not completed any of his past projects and does lot of delay.and also that before taking the amount the builder told me that loan from SBI will be possible(his banner stated pre-approved loans from SBI..etc),but after i paid the advance he was trying to persuade me to take loan from private banks for which i never agreed and when i was stressing that i will go for loan only from nationalised bank like SBI,he accepted and was trying to delay there also telling he will get approval for the apartment from SBI and then i can apply,i waited for sometime and then i cancelled the apartment,and the builder had issued post dated cheques taking the original agreement copy from me,the cheques bounced due to insufficient funds. and now it's almost a year even after serving notices from a lawyer to him from our side, he did not respond to any notice.he is scaring us that he has his own set of lawyers and knows how to tackle us and escape...he always tells us some date which he will return the money and then on that day he won't this has happened many times... Please can someone guide what to do...