Sorry to hear all those stuffs that happens to your parents Hajmola but seems like none of us on sajha have much idea about the refund policy of that airlines and neither do i. But so far as my knowledge i would suggest you to contact the place where your parents got the ticket from or contact the airlines company's branch office that's located in ktm or you can email the head office. Since it seems like you are in Canada so you can communicate well with those people than your parents, so i would say try to email the head office by email. good luck..