N.C. Gen. Stat. § 7A-212

No judgment of the district court rendered by a magistrate in a civil action assigned to him by the chief district judge is void, voidable, or irregular for the reason that the action is not one properly assignable to the magistrate under this article. The sole remedy for improper assignment is appeal for trial de novo before a district judge in the manner provided in this article. No judgment rendered by a magistrate in a civil action is valid when the action was not assigned to him by the chief district judge.