Myntra.com — showing refund initiated but not credited in account

Address: Panchmahal, Gujarat, 382721

I had returned two of my order on 29th of april but i didn't get the refund till date. When i called their customer care they told me that refund has been initiated and had given me some reference number and told me to contact the bank but bank also couldn't trace that number instead saying it can't be done. As it is very hard to follow up with bank every time, so what should i do to get my refund.