Consumer Redressal

I had purchased a nexus 5 case from latestone.com. as it was a defective case I opened a support case and had returned the same through courier. I got a reply for my support case asking for my bank details saying that money would be refunded within 7 days. But its already been more than 15 days , I am not getting any response from latestone support people. Later when I searched many people have been cheated like this only who has purchased goods from "latestone" Can some please guide me on this. 449 is not a big amount for me but, they are cheating many people like this, by sending defective piece's and once the goods is returned no response from them. So pleased some one help me on this.how can I complaint Om that website called "LatestOne"