Air India Express — Refund are not returning the refund

I have booked a ticket from Riyadh to Kannur on 24 April 2021, and I have cancelled the travel plan due to restrictions in India. and I have tried to cancel the ticket through their online portal, but their reservation system was down. Hence I have communicated through email to cancel the ticket and they have acknowledged the cancellation as well. but so far I have not received a refund from them. I have been trying to call them to enquire about the refund but they are not answering the call. for emails no reply at all. Hence I request you to do the needful for refunding the amount.
I can see that they are doing this for everyone. once they have the money, they are very reluctant to repay the money.