Refund delay

Dear Sir/Madam , I have booked flat in Feb 2013 by paying 20% of the Total cost (payments were done by cheques) and original receipts and submitted to SBI ( as I took Loan) and the project is an SBI approved Project. On June 2013 the builder as part of the contract took 1 instalment from the loan account for piling work and its now been 2yrs and there is no progress not even piling .And as per the agreement its clearly mentioned that I wl get the possession in 30 months from the commencement of work . Mean time my EMIs have started and on top of that bank also deducts extra interest amount as the builder has taken one Instalment so in a way I am paying both EMI and extra intrest on top of that which is going to grow in future if i continue with this project . So I have decided to withdraw myself from it and i have given a notice to the bank to stop any further disbursement of money and also notified the builder to refund my money .Now the builder is playing different tactis to delay the payments ,They are not giving me any written comunication and what ever verbal comunication i have with them they are requesting me to accept cheques in installments and they are not even providing me any intrest on top of that . Please advise what should I do because around 10L of my money is with them and its with tme for 2yrs now and there is no work not even piling forget about possesion . Please please advise . Thanks Sambit