Limit Increase - Declined after Approved

Good Day, App**** for Account Upgrade. Account was upgraded. New limit was approved and quotation was accepted. Today Private Banker came back saying that my Limit Increase was declined due to debt. I have no debt which does not make any sense. I always have problems with FNB. How was my account upgraded and limit increase approved and now declined. Pathetic Service once again from FNB.