Air India - Refund not issued

Had booked a ticket with Air India for flight from Delhi to Hong Kong, travel date Jan **, ****. The flight was cancelled last minute by Air India and the text messages from Air India prompted to call the customer and ask for refund. I duly called up, and a refund request was filed with reference number WB-IDEL**********. Since then, it has been * months, i have called customer care multiple times and either they say refund is under process, or they disconnect after a long wait time I have emailed multiple Air India stakeholders: reservations office, MDs of various department, even office of Ratan Tata. There is simply no action. They also direct you to raise a request through a 'feedback form' which i have done too. Mentioning two more such reference numbers: WB-DDEL**********, WB-IDEL**********.

Please help