[Resolved]  Amazon India — Order cancelled but still delivered and I'm being told I won't get a refund

I placed an order like any order time on Amazon and then realized I did not want the product anymore. Order was yet to be dispatched, and was successfully cancelled via Amazon App.
However, order was still delivered and left with the Security guard, no phone call, no OTP.
On trying to contact cust care for returns, I am being told that the order is not returnable and that I should have rejected the delivery.
This is outright cheating when you pay in advance, if I had marked this as COD, this problem would not have come up.
It's just such a blatant violation of consumer trust.