I understand you're just doing your duty in keeping the forum clean, but you have to see this from a player's perspective:
We have legitimate grievances, and a lot of us have spent money on this game. So if there is no feedback on private channels, like email, direct messaging, etc., it is natural that players will come here to complain about the state of the game.
If player base dissatisfaction is compromising the forums you run, then you should have a way to speak to the SuperMechs team and basically say, hey, these guys keep complaining about the game and it's hurting the forum, can you please check in on it?
There has to be some sort of oversight.
And I'm sure you understand this isn't just spam. We have very legitimate concerns: players are hacking the game and openly admit to it, and one particular player is selling accounts on facebook, which is demonstrable and against the terms and conditions of the game.
You might be stuck in an impossible place between having to keep forums clean and people happy, but we are stuck in an even worse place, where nobody is addressing our concerns at all.