Wrongly listed by ADT at the credit agency and not rectifying

ADT wrongly listed me with the credit agency for outstanding payment of R32k in July 2016. After many phone calls and long holds through the call centre Esther ZONDO assured me that my account was up to date and it was a neighbourhood's account that was behind. They would clear my name at the credit agency. ADT wasn't willing to provide proof though that they have cleared me with the credit agency. Now more than a year later to my surprise my bank declined an application for financing a new vehicle. Their credit check indicated an outstanding amount of R34k to ADT. It is obvious that ADT hasn't delivered on their promise more than a year ago that they have cleared everything. Now no one I can get hold of through the call centre is willing to commit to assist as a matter of urgency.