Commercial Office - Cheated by Pooja Aagam Group Builder in Surat

I had bought a Commercial Office in "Aagam Emporio" under construction by Pooja Aagam Group Builders on Udhana Magadella Road, Surat with a token payment of Rs. 1,00,000/- on December 26, 2013 followed by registration of conditional sales deed at Surat Registrar (Athwa) Office on the same day. After total Payment of Rs. 26,00,000/- by cheque (>50% of agreed sales amount) and duration of more than 10 months, the builder has shown his inability to build the project sighting unavailability of permission to build commercial building. Now I don’t know what to do and where to go to. If I had wanted interest, I would have invested the money in fixed deposit. Also the price, since have jumped and I can’t buy a new office with this same amount of money in the area. I am feeling cheated and helpless. The area has changed since my purchased with BRTS road, bus stop junction and four lanes. From a dull place to a bright prospective zone. Is there any other way to retain my office space rather than taking back my payment with interest?