It doesn't sound as if the WSDL generated by (2) above created a valid client. As I stated earlier, the native client generation does not work with all WSDL files especially those from WCF services. If you cannot generate a native client but you can generate a managed client then you might look at calling the managed client from the native program through COM Interop.
To test that the WSDL itself is valid you should download a tool such as SoapUI and import the WSDL there and try to run its client. If it works in SoapUI then it should probably also work in our client generator and then we could look into possible differences. If it also doesn't work in SoadUI then there is most likely a problem with the WSDL itself.