why are you so strict with me?
It's for you to learn a lesson.
I didnt do anything bad to anyone,
Yes you did. It may not be refer as "anyone" but to the forum itself.
there was an old mistake but I understood it and started everything in a new way, and you chase me from the forum as if I eat your food
It may be old or new, its all the same for us here. SBC is now cleaning the forum by finding plagiarized contents. So even if what you did is from a very long time ago, the evidence is still there.
Take note of this: if you killed somebody, can you restore its life? Of course its a no. Same goes for the forum. A rule should be abide by everyone. If you get banned you should not comeback. You may just read some contents but posting and doing any activities are prohibitted.