"Sorry, permission denied" message when loggin into forum

I have an envato account and have purchased many BeTheme installs. When I try to log into their forum https://forum.muffingroup.com/betheme I get a permission denied. What do I do? I have a legit user/pass and purchase code? Nothing is working… how do I contact someone for support?

You can also contact the theme developers (letting them know about the login issue) using this small contact form, at bottom-right, here: https://themeforest.net/user/muffingroup?#contact