Amazon India - Not recieved refund and amazon kept my product too which i send for refund

I,ve ordered wings company's earbuds, and paid already at the time of placed order, after few days i,ve received the order but my product was defective and not worked properly, after * or * days, i,ve send it for return and they send another piece of that earbuds, but that was also defective the mic of that earbuds not worked on calls, so i send my product for refund and they received my product, but after * days the status of my refund is showing that, your refund could not be processed, i dont know why, they did not said any reason of this.