That's really weird. The billing panel is up and running perfectly fine. Try to use another browser perhaps?
As we believe in open source we are using GamepanelX, but there is alot modified. We are also making our own panel in the meanwhile. We are planning to make everything custom made by the end of january.
In your homepage http://www.hostffs.com/main/ when i click Read More in MTA it says Something went wrong!