Amazon India — refund of rs 499 not received

Hi, My name is Shelza Murmu and I had a refund of Rs 499 from Amazon which they stated they had processed on 09/04/2019 but I did not get a single penny. They provided the refund reference number "141365" which is of no use. The SBI customer care says they want the UTR number and without it they can't locate the refund. I asked for a charge dispute, they said they can't file anything it's a third party thing. When you say the same to Amazon, they say it is the UTR number (number should be 16digit) and simply just say "we are sorry we can't help beyond this...contact SBI or contact Amazon". They start to put the burden on one another. I'm fed up now. I've called several times and as usual the same ans.
Please help me get my money back. I'm confused to whose fault is it?
My SBI Account number is ([protected])