Amazon India — order not delivered but status showing as delivered

I had placed an order for 3 books. I have received only one. When I checked 'track your orders' it's showing delivered on 2 nd September. I want to know why this delivered msg is shown for all the 3 though the delivery is still incomplete. Moreover tell me where are my rest of the books are. Otherwise I will cancel the order and then want the amount paid to be refunded. I had such a bitter experience that I will never ever do any shopping on Amazon. I will very soon discontinue Amazon Prime membership too. Horrible service.