Amazon — Money paid but handset not received

Address:	700156
Website:	amazon.in

I ordered lenove k4 handset through Amazon website on 11th Mar'16 by paying extra rs 50 for fastest delivery charge. I got the product on 14th Mar'16. after using for 2hrs the handset was found defective. I filed the return request. I returned back the handset on 15th Mar'16 to Amazon courier team. Also I got an message that I will get another handset of Lenove k4 by 19th Mar'16.ORDER #[protected].
Today is 25th Mar'16, there is no information is available & I didn't get my order till date. And I have taken this handset through HDFC EMI system. My EMI is already started but i have not received my Handset. When I calling/emailing customer care, I didn't get any positive response from them.