Flipkart — refund not received and never initiated

Dear sir,

I am writing with regards to non issue of refund against my flipkart pay later account of amount 512/- for which i had already paid money via debit card.
As per myntra and flipkart, the refund amount was transferred back to my bank account on 6th nov 19 however my bank has not received any such reverse transaction. I have written n number of emails to myntra and flipkart but they are not replying to my query.

The amount may be small for them but it is not same for me... They have mentally harassed me and are not returning my money.