Flats booked but no posession as builder not responding. What to do ?

Dear Sir, We have booked a flat in a townshop in Greater Noida. We paid some initial amount to Builder. But that has come under disputed area (Sahberi village). After these units have come under disputed area, we have contacted builder for resolution, we have got call from bulider executives for providing alternate Flat, for which we have agreed and confirmed. But there were no alternate unit allotted to me and Now builder is also not responding. I want that atl east my money along with interest builder should pay. How you can support me. What will be the fee.