Yatra.com - Yatra com Incomplete refund for cancelled flight

I had booked Mumbai to Gorakhpur flight and paid *****/-. The airline preponed the flight by *hr and **min,due to this I have to cancel my flight as it was very difficult to catch my flight. The airline refunded the complete amount for this. However Yatra.com deducted ****/- as their convenience fee and refunded the remaining amount. This is unfair as airline has refunded full amount.