Punjab National Bank [PNB] — A refund from Amazon not reflected into my PNB account since 21 days

A refund was initiated from Amazon on 12th September 2021 amounting INR 961 which was supposed to be credited into my account by 17th of September but the amount hasn't been reflected in my pnb bank account yet.
On speaking with the Amazon's customer service team, they have informed that the transaction is pending from the bank's end and asked me to contact PNB customer service center. On contacting them, they deny of any help and asked me to contact my branch.
On contacting the branch, they say they cannot track the refund.
Then I contacted PNB via their email on September 24th. I received a reply on 25th September, asking for my account number to help me further, I reverted back 6 days later. Since then I haven't heard from them and I have been checking my account statement; which doesn't shows anything.
I am attaching the screenshots below

I request you to look into the matter.