Yatra Online / Yatratrip.in — Fraud company they cut almost 1700 on flight cancellation in 1/2 an hour

I booked a flight on yatra.com on 26 Aug. I booked my flight for Rs 5881.07
But by mistake I have booked twice
And I cancelled one flight. On that flight I used my credit card for some discount Reason. I got a discount of Rs 975 on flight ticket. I cancelled the flight within 1/2 an hour of booking and yatra charged over 1600 for cancellation. I called yatra and asked why so high cancellation charges. They said discount amount is non refundable(Rs 975), airline charges Rs.500 and yatra convenience fee of rs Rs.450 something. I am a student and by seeing this much cancellation rate on yatra. Yatra don't Even bold these kind of important details while giving discounts. Yatra is a big fraud company.

Booking Id:[protected]
Flight booked on :26 Aug
Flight PNR:BZRBMX