Indian Bank — Myntra Refund

I have ordered two dresses from mynthra on November 12th and returned the product after few days as it is showing in the app that refund is processed on December 7th and contacted mynthra’s customer care several time they have the reference number as proof to check with Indian bank as I paid through UPI from Indian bank account .
As I checked with the bank, also the head office it was told with that reference number no refunds has been credited. But mynthra’s customer care asked me for a written statement but that is not been provided by indian bank so from mynthra’s end refund has been initiated to my Indian bank account which is not reflecting