Indian Railway Catering & Tourism Corporation [IRCTC] — refund of my ticket amount as my train was cancelled

I have booked e/ticket on 25.08.2018 from guwahati to new tinsukia through irctc portal. The details of the ticket are:

Pnr number: [protected]transaction id: [protected]
Train number/name: 15959 / kamrup expressbooking date: 17 aug 2018
From: guwahati (Ghy) 25 aug 2018to: new tinsukia jn (Ntsk) 26 aug 2018 04:25 hrs

Due to some accident in the route my train was cancelled and i could not come by that train. So, on enquiry at railway station, the railway personal told me that the ticket amount will be refunded through online as my ticket was booked online. But it's been a month and still i have not received my refund.