Amazon - Undelivered product and no refund replacement

I ordered one product from amazon, It was out for delivery on **th Feb. The delivery boy refused to deliver at resident address which is on *th floor. We told him to keep it at the glossary store at base of the building. He didn't kept it there and marked as delivered. We tried contacting him on the number we got at the time of delivery, he didn't responded. We immediately raised the dispute to amazon. They told to wait for ** hrs, then told to wait for * days. Then the told its under investigation and lastly they emailed that investigation is completed and product is delivered and they will not issue refund/replacement. Now, I am contacting customer care regularly but they are not responding.