Flipkart - Refund not received

What should I do when Flipkart is not refunding my money? When I contact them, they are always saying they have credited the money, but when I check with my bank, they say no amount has been credited. It has already been * months.
Date of incident : **th May ****
(Initiated on **th may ****) but not processed to my account.

Transaction date: **th May *****
Merchant name : *Flipkart India private limited*
Transaction amount : ****** RUPEES *
Disputed amount:***** RUPEES*
Date of refund initiated: **th May ****
Mode of refund: UPI INTENT
ARN number : *************
Account number:  *****ending*****
Card number: *ending with *****.