Sorry to hear you are having problems but there are loads of people that are having no issues with their devices and they are working just fine. Out of interest I looked at the reviews on Amazon and there were loads of great reviews for this product. I found a recent bad WD Cloud review on the site and the guy complained about 4 out of the 5 products he had ordered, either he is very unlucky or he is hard to please.
Good luck with your Mycloud replacement I hope the replacement fulfills your needs.