Sun Trust sued to collect on deficiencies following a foreclosure in North Carolina. The Debtors raised defenses challenging the validity of the debt and the default. The Court of Appeals held that the determination of a valid debt and default at the foreclosure hearing was res judicata. While the Debtors could not have raised these equitable defenses in the hearing under N.C.G.S. § 45-21.16, they could have raised such defenses in a proceeding to enjoin the foreclosure under N.C.G.S.