If any man doesn't obey our word in this letter, note that man, that you have no company with him, to the end that he may be ashamed.
The purpose of all discipline is to cause the one in question to return and correct his error. We are not told to abuse or mistreat anyone, but we are told to ignore and refrain from association with him in order to make him ashamed. The door of opportunity will always be opened to correct this sin before or after discipline has been implemented.