This is the error I had encountered when I was configuring wshttpbinding with Azure WCF Web role as per the steps I mentioned here - http://sanganakauthority.blogspot.in/2014/03/azure-wcf-web-role-with-wshttpbinding.html
This problem is encountered when metadata endpoint is not configured on WCF web config file. So you need to configure mex endpoint and mark httpGetEnabled as true.
<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
And in service behaviour mark httpGetenabled=true. This should solve the problem.
Hope this helps.