Hey there, Kitmine99! Sorry to hear that this happened on your server. We aren't able to do anything for your server in this instance, however, we can offer some preventative measures to take! There are a few things that I can suggest to ensure this does not happen again. The first is to use the white/black list function that Mcthistle mentioned above. You can read this FAQ article on the subject. This is a great way to ensure that only approved users are able to join your server. Further, you can also get the plugin CoreProtect. This plugin is great for greif protection. You can learn more about it here, and install it in your Minehut dashboard.
Happy Crafting!