Also, I don't know that copied articles is forbidden here, because i saw many articals in press section is copied from the net, I've been surprised by this permanent ban.
Articles in the press section make it clear that the content is not original and they give a source. Further, they are posted in a designated section where this is allowed.
You did neither.
I am a seller, and i need to contact buyers and reply to messages.
No, you don't. Also, refrain from evading your ban with this (or other) account.