Myntra.com — refund policy

It has been 15 days i haven't received the refund amount for 2 products. When i am calling to myntra they are saying that check it with the bank and the guys from bank are not aware about it. I have one question that why it happens only with myntra. I have used all the shopping sites there return policy is good. I don't have to suffer but for myntra it's have been a very frustrating experience with the return policies. This is the second time it is happening.