Webservice and WCF Service Preview

Hello,

I have to use WCF Service preview of VS2015. I had done e Web API .NET Core 1.0 and I need to connect to Webservice of NAV 2016.
I managed the WCF Service connection made a NAV.wsdl file and my project has a connection to NAV, but I don't know how to istance a connection client in C#.
I have attached two image, one of WCF service and one of api/controller where I tryed to call a NAV2016 web service.

Can you explain me like to call a web service?

thanks in advance