I had booked a ticket using ICICI free ticket code and now want to change the flight. Price for the new flight is lower than the previously booked flight.

I read the terms and understand that flight change is possible but if ticket is canceled then the code cannot be used again.

I called Jet Airways to change and they said I need to pay full fare of the new flight plus cancelation charge of the previously booked flight. This is the same as cancelation terms as per the bank.

Can anybody suggest what should be done in this case?