Yes I had the same problem with the plugin with loads of hack attacks, but no way do I blame the plugin for that because it's a good plugin. The hackers got into my Wordfence plugin and changed everything so that the plugin actually started working for the hackers instead.
So I uninstalled and reinstalled Wordfence plugin and it was OK after that. It's a great plugin and I will be upgrading to the pro version, but I have to agree with you that the support for the Wordfence plugin is absolutely dreadful and completely hopeless.