This actually happened to me recently. I was banned from Hedgehog Cafe without a warning and without a reason, so now I made light of the situation and turned it into a game. Here, simply make up ridiculous reasons for why you, me, or someone else has been banned for a site. I'll go first:
You cursed the site owner when they didn't read your topic, therefore giving them cancer.
You cursed the site owner when they didn't read your topic, therefore giving them cancer.