Punjab National Bank [PNB] — Refund from online purchase

Address:	Indore, Madhya Pradesh, 453332
Website:	www.pnbindia.in

Purchased canon dslr camera ₹22990 from amazon on 18/12/2016 and done full payment by debit card but order was cancelled on 23/12/2016 and now amazon is saying that refund has been sent to bank. So contact customer service and file charge dispute they had given me a no. Refund reference# 75260826359010816065230
But customer service is saying they can file nothing like charge dispute and can only check if money came to your account or not.
Same behaviour by branch also.
Don't know what to do