Can't remove Half-root caused by KingoRoot

I have a Huawei AT&T Fusion 3 (Y536A1) with Android 4.4.3 which I attempted to root with KingoRoot but it ended up giving me a half-root after testing it with the Freedom app. I tried uninstalling it using the KingoRoot Superuser, but it just deletes the Superuser app and restarts but doesn't delete the root itself. I tried manually deleting the su files (with Root Explorer and ES File Explorer), but I don't have the right permissions to do so. I also tried using SuperSU but the binaries always failed to update and when I tried full unroot it still didn't unroot. I also tried to install KingRoot over KingoRoot but it said that it couldn't root (even though the device is compatible). How do I remove this half root so I can fully root?