GoAir — didn't paid my full refund

I had my flight on the 23 from del to gau via ixb but the airline cancelled the flight from del to ixb so how am i supposed to reach gau if they cancelled it so i called the flight for which i paid 4300 and i should be refunded at least 50% of the fare but they refunded me only rs 230, that's not acceptable as it was their fault for cancelling the flight to ixb so i demand a refund of 50 % anyhow