Punjab National Bank [PNB] — refund money not credited in account

Complaint regarding my electricity bill payment of rs.1236
On date 13 april 2020

In which my money is deducted from account but transaction failed. I contacted the amazon costumer care service they told me that they have already paid it to punjab national bank only bank need to update that they send me this

Refund reference number 512113

I called costumer service of punjab national bank 3 times. But they are not listening to my request.