State Bank Of India [SBI] — amount not received yet from amazon

I have purchased some accessories and I paid online by debit card.
But after I returned my order. And Amazon initiated my amount on 25th Oct. But I haven't received my amount in my sbi account yet. It's too late. On Amazon account they write one thing that you get ur refund after 3-5 business days but its aprox 15-16 days but I haven't received my refund. I want my refund of 870 rupees in my sbi account as soon as possible.