Bank Of India — Refund initiated or processed by amazon but still not received in bank account

I had orderd a product from amazon, product value:499, but because of some reason i had return it on 16 of may, and i had told that you will receive refund by 21 may, but still now i didn't get the refund, when i contact amazon they gave this refund reference no.[protected].and they said it is stuck in bank process but bnk is not responsing properly, please help me