Jet Airways — nonrefundable flight ticket

Address: 2/43, ALANKADAVU, DEVANSAPUDUR P.O, 642103

I booked a ticket for our journey from coimbatore to mumbai for the date of journey on 03/04/19 via pnr no ydjpmg in the flight no.9w 419 but the same flight had been cancelled one week before the date of journey and the cost of booked ticket did not return by the authorities of jet airways till date. I called the jet airways in their c/care no more than 04 times and they assured for refund the amount. But still not yet refunded the same. Kindly intervene the matter being a request of a citizen.