All such unknown persons so served shall have the same right to appear and defend before and after judgment as would named defendants upon whom service is made by publication, and any order or judgment in the action shall be binding upon those who have been served or who shall appear and defend, whether they be of age or minors, and, if they be minors when judgment is rendered, they may be allowed to defend at any time within three years after coming of age.
S.C. Code § 15-67-50