Myntra.com — wrong product picked up by myntra courier partner.

Wrong product picked up by myntra courier partner and they are not refunding for the product which got picked up. I raised complain but they closed the complain without proper investigation. I have sent even sent the screenshot of the product which has not picked up and for which i got refund.
The product which got picked up was of 1847 but they refunded me back only 767 price of the product which has not picked up.