Air India — refund not received for over 1.5 month

I had booked 4 tickets mumbai hong kong along with return tickets.
My return flight was on 3rd november 2019, which was cancelled by air india.
The details are as follows.
Flight # ai311
Date - 03 nov 2019
Pnr # y4277

It has been 1.5 months but i have still not got my refund. Your call center has no answer to my refund query. I have written earlier to ecommerce but no reply for same. I tried calling you guys but no answer.

I need an answer as to by when and how will i be receiving my own money.
This is absolute harassment of customer