[Resolved]  Ezeego1.com — charges for cancellation of air ticket

I booked my air ticket on ezeego1.com from Bangalore to New Delhi for travel on 17th October, 2009.
The ticket was booked on the 9th of October. I paid an amount of Rs 6313.00 for the ticket for Go Air for its flight departing at 08.35 in the morning.
There was a scheme at the time of booking which said "if I book through SBI credit card, I get a maximum of Rs 500 discount of my basic fare". I availed this discount.
Due to some reason I had to cancel the ticket on the 16th of October.
I called up the ezeego emergency no. 5757567. I cancelled the ticket. the amount credited to my credit card was only Rs 4856.00 The calculation done was as follows:
750.00 Airlines cancellation charges
500.00 For availing the SBI discount
207.00 Ezeego booking charges
How is the amount of 500 justified ????????

What action should I take to recover this unjustified charges levied.