Punjab National Bank [PNB] — refund for cancellation not received

My mobile number is [protected]. A refund from amazon.in was initiated on 22nd jan 2019. But till 30th jan, i did not get any refund. I request you to help me
The reference number is 75503729023026441112279. My account is in pnb bank. The bank people said they have nothing to do with the reference number. They were asking to contact amazon.in but amazon is telling contact pnb.