The pre-built web API calls for PHP, C#, and VB.NET are definitely lagging behind what's available on the server. That's just because we've prioritized everything else over keeping the "example helpers" up-to-date.
We do plan on updating those example helpers later this year.
In the meantime they're fairly easy to follow. Use the web API docs as the primary reference (because they are), and modify/add/remove functions parameters, etc. to the example.
For example, "GetPKeyID()" in C#, VB.NET, and PHP used to require the version_id because the web API used to require it as well. That's no longer the case, so you can just remove it.