Amazon India — full refund not received and not cancel emi

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online, 600073

I have order samsung m30s phone on amazon at 28th sep 2019, for rupees 12, 100.23 with my sbi card and choose no cost emi.
But that day evening i have to cancel this order due to some personal reason.
But the amazon refund the partial amount to bank 11, 100.23 only and say
Un acceptable reason, then i spoke to bank for cancel emi, but the banker
Need to refund full amount then only possible to cancel emi.

I need to cancel this emi, amazon only do this.
Why i can pay for interest to bank, i am not purchase any item.