I have booked two tickets on third A/C in train no 12674 .Date of Journey 22.01.2018 . Coimbatore to Chennai, , Departure 22.40, total fare for two tickets Rs 980 under senior citizen category. PNR number 4552011283. Due to unavoidable circumstances I am unable to travel and want to cancel the ticket at about 12.30 PM of Sunday 21.01.2018 through on line . But to my surprise in the PNR number during cancellation it shows , CACELLATION NOT ALLOWED. . why cancellation not allowed , Time available for train departure more than 30 hours . I want the about ticket cancelled and amount refunded as per existing. rules of more than 24 hours