Amazon India — samsung m30s - cash back issue

Order no.[protected]
I ordered samsung m30 s mobile in amazon on 30-sep-2019 (Offer is 1000 rupees cash back in amazon wallet will reflect after 3 days of shipping of the product and sbi card 10 percent instant discount)

As per above offer instant discount received but cash back not received

I called to customer care
In 1st call she said to me that is for prime members (But our colleague has not a prime member but he got the cash back on same product)
In 2nd call he questioned me where you seen this offer and asked me to send the screen shots through mail offer related ([protected]@amazon.in) after sending the mail no response from amazon cs team.
In 3rd call she asked me above all and finally she asked me cash back received product order id

Screen shots enclosed which i was sent to cs team

They are prolonging the issue but not getting the exact reason