I am not sure if the Czechs are just rude people, but in the rest of the world, we have these things called manners and something called humility.
When one of your paying customers posts a message on your forum and their spelling isn't very good, you should not berate them or insult them. If someone posts in an incorrect part of the forum, you should not talk down to them like they are a naughty child. And if someone criticises your belligerent and rude moderation policy, they should not be permanently IP banned so that they are not even able to VIEW the forum even while logged out.
Besides the fact that doing this to a paying customer is potentially not even 100% legal, there is also the matter of what is right and just and fair. Whether you have lost sight of this, or never had it to begin with, I don't know. But I am telling you now, your policy on how you treat the public is absolutely disgusting, and I hope that either you will learn how to fix it, or karma will deal you some justice.