Punjab National Bank [PNB] — Refund not yet credited in my bank account

Website:

www.pnbindia.in

My name is arghya nandy. I ordered a 'canon power shot g7x mark ii digital 20.1 mp camera' of rs 36969 on 17th july. Later within 2 hours i cancelled my order and amazon initiated the refund on 18th july to my card but i still didn't get the money. Amazon sent me a refund reference number #75503720200041012979091 and told me to file a charge dispute form but punjab national bank doesn't have such policy.
My debit card number: [protected]
My account number: [protected]
Please kindly respond to this complaint. It's very urgent. It's like one-third of the money in my bank account.