Flipkart — Refund not completed after return pickup post 16 days

Received SleepyHead matress through Flipkart on July 14th 2022, found it faulty and used like, so initiated return, received return request approved message and return pick up message, courier person picked up return on July 15th, its been 16 days - there is no refund yet. Spoke with customer care 6 times over last week, the only answer they provide is we are looking into it, we will provide resolution in 48 hours - its been two weeks - no change.