Air India — no refund from air india

Air India Refund not yet received after 37 days .
They have past their 21 days policy and the customer care staff are not of much help .
They keep lying that I will get the refund after two days and then I never got my refund.
I've called them 10 times.

I've only got excuses from the staff.
One staff told me to go ahead and file a complaint if i wanted. It was very rude of her.

I cancelled my flight on 24th December, 2019 for a flight due on 28th December, 2019. According to the policy, cancellation of flight before 24 hours of departure is refundable in 21 days maximum and i booked a flight which was refundable. Its been 37 days which is more than a month.