Frustrated with lack of action

I am a member of SAA Voyager and since June this year I have been trying repeatedly to effect a surname change so I can claim miles. As requested, I have sent through the supporting documentation to no avail. I have called the call centre and have either been asked to re-send the documents, or give them some time to effect the change. Nothing. Once I was even given the email address of a supervisor so that the complaint could be dealt with urgently and that did not help either.