Consumer Redressal

My brother-in-law has booked an international flight from Makemytrip site with Booking ID IN1501B7S290584 amount Rs.43000.00 which was later cancelled in Febraury. The amount is not been transferred back to my credit card account, many months have passed but only 1500.00 is been credited back to my account, whereas during cancellation the person with whom we were dealing, he told us that 3000.00 will be charged as cancellation charges and 40000.00 will be refunded back to your account. I have also incurred Rs 8000 interest on my Credit Card because of this amount. I have called and e-mailed Makemy trip but have received no response from them