Punjab National Bank [PNB] — refund from online shopping (amazon)

I purchased a dulcet car stereo of rs 5490 on 20/06/2019 from amazon.in i completed my full payment through upi. And the order was cancelled on 25/06/2019
Till now i have not received my refund amount
I contacted amazon several time they said your refund has been initiated on 25/06/2019 and gave me the refund reference number[protected]
And suggest me to contact pnb support and file a cash dispute
So i contacted pnb support but they said they can not help me with amazon generated reference number. The only thing they can do is to check my account balance.
Help me out
I do not want to loose my money for no reason