Cancellation of sale agreement of a flat

Hello all We had booked a flat in 2013 and had entered into an agreement. Due to change in circumstances we had asked for cancellation of the same in April 2014. We have made payments to the builder as per his schedule (around 38 lakhs) until the cancellation date. However..even after almost a year the builder has not refunded our amount. Also he had stated that the amount will be refunded only after getting a prospective buyer. In Dec 2014 we were informed that we would be refunded without waiting for other buyers for our flat. However its almost 2 months and we still have not got anything back except for postponement of refund dates. We have moved out of India and therefore the communication is only thru phone or mail to the subordinates of the builder. My question is... 1. Is it possible to sell our flat to other prospective buyer without our knowledge as we have opted for cancellation? 2. What are the legal options available? Would going to a consumer court be better or should I go to a civil court? And approximately how much time period would it take to resolve our case. 3. We were informed orally that about 20% of the total flat cost would be deducted if we opt for cancellation. However there are no such clauses in the agreement. Would there be any other clauses evoked which are not there in the agreement for our cancellation?