Actually to them, you might be just another noisy mosquito
buzzing around their ear. Whether you speak the truth or not, they
would know. anyway, that might not be the reason why they ban you.
First of all, the website belongs to them, they can ban anyone
based on whatever reason reason they concoct, whether it makes
sense to us or not, it doesn't matter. Not too long ago, I was
banned from commenting on a popular blogger's comment box, from his
reaction, i can see that he did it because of his own insecurities
and that he was being very protective of his blog. But i did not go
to any forum to complain about him, he is quite well known i could
have easily done that but i didn't.
Instead of complaining about being banned, why don't you do
something more useful about it, like set up your own website or
write in the opposition's website/blog. I think you need to come
down to earth and accept that this is one of the 'rules' of the
internet, you may get banned from any website for any reason. the
sooner you realize it, the better it is for you.