Indigo Airlines — late flight for cancellation

Hello,

My pnr is 17kcqi.
I have book the return ticket from kolkata to hyderabad.
Flight 6e373 is too much delayed on 8th august at kolkata airport.

For the delay of 6e 373 i have canceled the boarding at kolkata airport.
Please cancel the both way tickets and refund full amount.

I have already talk with customer care of indigo.
But they have not agree to give full refund.

I am waiting for your reply.

With regards,
Abdul malek