NEDBANK admin error and unfair treatment of a client

I have been harassed by debt collectors and demands over the last year or more only to find that Nedbank have somehow linked my profile to someone else's debt. Numerous calls, numerous visits to the PE branches, numerous emails then an email from Nedbank confirming the error was in fact theirs. A few weeks later a very rude call from their legal branch challenging me by saying " you are surely intelligent enough to know that you need to service your account" what account I asked, he didn't have the details in front of him!! Who is going to help me? I have been mistreated, ignored, fallen prey to Nedbank's admin error and charged incorrectly for someone else's debt plus interest plus bank changes for an account that I could not close until the matter has been resolved. Shocking!