One thing more to check is your Firewall settings on your computer and if its possible, to try to run the game on another computer to see if its a computer related problem or internet related.
Some internet service providers block certain applications to work, for exaple, the school's internet blocks games, Axtel block torrents, etc. Maybe they could be mistaking Feralheart or its protocols as something unallowed.
I really have no idea of what else could be wrong, so im guessing they are blocking feralheart.
So you should call them and ask if they are blocking any kind of UDP or game connection, specially feral-heart.com or raznet.co.uk on the ports 30000 and up
Feral heart only requires very little bandwidth to work properly, 32kbps (4KB/s) is enough and being unable to connect is really related to something blocking the conection.