Amazon India — refund of cancelled item ifb microwave oven

I had ordered ifb microwave oven (Order #[protected] on 9 aug and cancelled the same on 11 aug, because due to some bank transaction problem i had to order the item twice and subsequently the amount was deducted from my bank account twice. I don’t understand that why did amazon sent the item on 29 aug which was ordered on 9 aug and secondly the item which i had already cancelled
On 11 aug. And till date my amount has not been refunded in spite of contacting amazon customer service number of times. They talk about rules of regarding refunds but no one gave a proper reply about sending the item which have cancelled in advance,