Not refund of ticket fare against cancellation

Location/place: Guwahati/Mazirgaon/Assam

Name of company/service: Indigo Flight

Sir I am Nitu moni bordoloi,Purchase a Indigo Airlince ticket for Guwahati-Channai(Up/Dn)but due to my father illness we have cancelled the ticket.but after cancellation they didnot refund us the payable fare to us and giving us a PNR no & told that we can travel by this no within one year.and said that the ticket is non refundable.but when we asked them to see where it is mention in the ticket thay could not saw us.and after that they itself write in the ticket and stamped it.Sir we buy the ticket direct from indigo counter situated at guwahati airport and in the terms & condition column of the ticket there is clearly mentioned that after cancellation the passanger can get refund the fair.Plz do something-09957492160