Myntra.com — Money got debited for unsuccessful orders

My amount got debited twice while ordering a product in Myntra from my kotak mahindra bank account. I made the transaction through UPI. It has been more than one month I checked with bank several times they are saying that Myntra received the amount and they have to refund it, but Myntra people are saying that they didn't received the amount so they can't refund it.
I raised an issue several times regarding this but no use. What should I do. Myntra I want my money back.