This is one that comes to mind, when it comes to shunning wrong doers who have been spoken to by the elders. This verse is used.
Matt 18:17
“If he does not listen to them, speak to the congregation. If he does not listen even to the congregation, let him be to you just as a man of the nations and as a tax collector”.
Watchtower tell us that the "man of the nations and the tax collector” here are symbolic for disfellowshipped ones. But nowhere does the Bible support the idea that we shun people of the nations or tax collectors, even Jesus associated a lot with these people.