I've been banking with Nedbank 10 years and they have been really good to me until lately

I've been banking with Nedbank 10 years and they have been really good to me until lately. I have a personal loan with them which I pay without fail. My agreement with them states that it's deducted on the 25th of each month, however because I usually get my salary before the 25th they would deduct earlier on the 23rd. It happened that I got my salary on the 24th last month (August) and as soon as the salary came in they deducted it. But they had already sent my profile as unpaid to the credit burea (Experian) and that made my credit record to be 8points low. I called Nedbank and asked them about the information that reflected on the credit profile and they confirmed that I am not in arrears but and they explained that because they did not get the money on the 23rd the system recorded it as unpaid. They were able to update their internal system but the information at the credit burea is still unchanged 30days after their mistake. I try very hard to maintain a good credit record and Nedbank has just destroyed because of their stupid mistake