NO UPDATE FROM FNB

I’m really happy with how FNB works. For them to clear your name you have to struggle. I paid FNB via DMC Debt Management the account was paid up in full and I got settlement letters from both parties. Now I went through my credit report only to find out that I was behind with payments on the same account. Yet I was paying every month how is that possible? I contacted FNB on X and their response was I have to contact DMC which I did and from DMC the response was FNB is the one responsible to update everything at their head offices. It’s been 4 months after I got settlement letters no update in my credit report. WHO TO CONTACT?