Make My Trip & IndiGo Airway — Penalty of cancellation

Address:

Gujarat

I have booked a ticket from ahmedabad to mumbai in indigo airways in rs2074/person with tax through makemytrip on 10/09/2013 at 3:59pm for 3 people. And the day of trip is 10-15days from the date of booking. But for obvious reason i have to cancelled one passenger from tour. So i have cancel a ticket on the same day at 5:45pm. They refund me back just rs323. So i have called to makemytrip for inquire abotu the penelty and they reply me that 1500rs was the penelty by airlines and 250rs penelty is by them. This is rediculus. How can the airline charge me 1500rs and the agent 250rs for just rs2074 ticket. Which is 10 to 15 days from the day of booking.