No delivery and inconviniance caused

I had a laptop contract with vodacom and settled the account last year to my surprise vodacom didn't update my credit record as I appeared as being in areas since July 2014 and I disputed that information at TransUnion and again when I requested for a settlement letter last week I was told that I will get it within 3days and I'm still waiting and I contacted collections dpt again this morning only to find that the consultant who helped me last week wrote my email incorrectly then again I was told I will get it before 12 midday and I didn't and again I contacted them and I was told I will get it tomorrow, I asked for complaints dpt and was told to contact 111 even there I was told to call collections dpt. What do I have to do to get a settlement letter ? My problem solution depends on this letter that were caused by you not updating my credit profile.