How to programmatically activate license for Bigip using C#

I am looking for some C sample to activate license for Bigip. I have looked into the pycontrol https://devcentral.f5.com/wiki/iControl.pyControl-v2-License-BIGIP.ashx and am trying to do the similar thing in C. The wiki mentions a web service https://activate.f5.com/license/services/urn:com.f5.license.v5b.ActivationService?wsdl, but when I tries to use wsdl.exe to create a proxy class for this web service, I got the following errors:

D:\temp>wsdl https://activate.f5.com/license/services/urn:com.f5.license.v5b.Act
ivationService?wsdl
Microsoft (R) Web Services Description Language Utility
[Microsoft (R) .NET Framework, Version 4.0.30319.17929]
Copyright (C) Microsoft Corporation. All rights reserved.
Error: There was an error processing 'https://activate.f5.com/license/services/u
rn:com.f5.license.v5b.ActivationService?wsdl'.
  - The document at the url https://activate.f5.com/license/services/urn:com.f5.
license.v5b.ActivationService?wsdl was not recognized as a known document type.
The error message from each known type may help you fix the problem:
- Report from 'XML Schema' is 'The root element of a W3C XML Schema should be s
chema and its namespace should be 'http://www.w3.org/2001/XMLSchema'.'.
- Report from 'DISCO Document' is 'Discovery document at the URL https://activat
e.f5.com/license/services/urn:com.f5.license.v5b.ActivationService?wsdl could no
t be found.'.
  - The document format is not recognized.
- Report from 'WSDL Document' is 'There is an error in XML document (58, 16).'.
  - Namespace prefix 'intf:urn' is not defined.

If you would like more help, please type "wsdl /?".

Does anyone know if how to solve the problem? or is it the right way to access the web service at all in C?

thanks Wai