How to get my flat or recovery my money

Sir,, I have made agreement for the Flat in Feb 2013 for 29 Lakhs in visakhapatnam near Midilapur vuda colony. Flat Registration done on Jun 2012 at slab level and paid 14 lakhs. After that for nearly two years he did not done any progress in construction. In 2014 he started again. I paid another 6 lakhs as he stared. But again stopped. He is not completing the flat. He suppose to hand over by 2014. Now its 2016. Now i lost my hope of this person about completing the project. He is not responding to the phone. Can not find him. He moved to another place. i do not have his new place communication address. In between i have asked him to handover as it is stage and i will do my self. and i will not pay anymore. But he did not respond. Now from last 6 months not responding to the phone calls. All payments made by cheques. Expect Registration Charges & Service Tax. Its 15 Flats Apartment no one occupied and nothing is ready to occupy. I wud like to go for legally on this how i can approach. I do not have numbers for the other flat owners to contact. Keerthi Constructions , Builder : Mutyalapalli Srinivasa Rao My e-mail address : nageshpad@gmail.com i request you to kindly help me to give suggestions to get my flat or my money. Thanks & Rgds P.V.P. Nageswara Rao