Punjab National Bank [PNB] — refund credited issue

Hello sir, i am this writing because i am feeling helpless, the issue is i am not getting my refund in my bank account. I purchased a item from Amazon shopping and cancelled it on next day. Amazon send me a confirmation mail of my refund which they was initiating from their side. Amazon also give a reference number with mail and mention that if i am not getting the money refund within 2-4 days then call PNB and show the reference number. I called 2 times PNB and not getting a helpfull response regarding my refund, they said call Amazon for this. both parties blaming each other on this. Now i am feeling helpless. Please help me on this matter and help to get my refund back. Below is some details for your reference.

Bank- PNB
A/c- [protected]
Amazon Refund Ref no- #[protected]