Titus 3:10 A man that is an heretick after the first and second admonition reject; 11 Knowing that he that is such is subverted, and sinneth, being condemned of himself.
We are not told to continue trying to admonish people pushing certain divisive things after the second time. It is three strikes you are out. You may wonder why they just can't see, Paul tells us, they are subverted, they are sinning, and they are condemned of themselves.