Air India — Refund of Ticket Covid 19

Address: Mumbai

I had booking which was cancelled in lockdown period and its been 10 months now I haven't received refund.
Below is my ticket details ;
PNR : YCKPZ
BOOKING NO :[protected]
Passenger : Prashant Pathak
Travel Date : 27 Mar 2020
Mumbai to Kolkata

I had sent multiple mails to customer care (eCommerce eCommerce,
[protected]@airindia.in) but got no resolution . Initially they said refund was done on 22 Sep 2020, but when I checked with my bank, bank confirmed the refund isn't done. On further discussing with escalation team of Air India (via multiple calls) they confirmed that refund wasn't successful and same will be done by Nov 29.

But that didn't happen, I am being put through lot of trouble and stress talking and discussing my problem, but no heed is given to my case