Air India Express — No Refund yet while the Flight is cancelled

I booked 2 tickets from Sharjah to Chennai PNR 34PZ7Y and Chennai to Sharjah PNR M0Z9GS.

The Flights got cancelled. Though I cancelled the tickets, no refund yet even after 20 days.

And again this service provider is so negligible in handling the customer. Haven't received the refund from the airline after the timeline has been exceeded. After a continuous follow-up of several calls, I am still left with neither the answer nor the refund.

With TATA it has become worse