Air India Express — Complaint regarding cancelled flight ticket refund

Sir,
I had booked 5 seats in two tickets from trivandrum to chennai for 12/12/2016 in air india express with PNR nos 1FGFIL and 2W797G. But the flight was cancelld because of bad weather. . On the way to air port only they informed me..then i tried to book another day, for that i phoned to tvm office, but no information, then i tried online... that was also fullfilled. then i came back to chennai by train. Then i email the details to the chennai office but no information.
Till now the cancelled ticket refund did not got in my account.
please do the needful to get me the amount