To avoid bans, Don't share repetitive, deceptive and irrelevant content, don't send message/comments in bulk, using third party software which is not approved by pin, Improper link placement and sharing private information which means 100% violence and disallowed content. While using these things, your account will get banned.
To reactivate suspended pin account, in contact page fill the contact form to let them know that your account has been suspended. In that form, put detailed message about reactivated my account in the description box and submit it.