I saw that there is a way to clear contancts from a given list, but I was wondering is there was a way to do it using the C# library?
This functionality was missing in the .NET Library. Sorry about that. I have made some changes to the utilites and committed the updates to github. You can find the changes here, and use the function clearContacts(authentication, listids). Let me know if it's not functioning correctly, and we can get things working.