Ivc telcom city (employees cooperative society)

Hi All As we booked the site of 40*60 in IVC Telcom city employees cooperative society near thindlu cross Devanahalli Bangalore on an installment basis every six months on 2015 we paid amount of 4, 80,000/- they told us that they will hand over the layout within three years but till date no development has been made even they are not showing us the legal property papers about their progress, total amount paid Rs14,40,000/- kindly help me will I get the refund amount paid to IVC Telcom city employees cooperative society with an interest please tell me how to get the refund amount and what will be the procedure to the process ahead.