My credit score has been reduced because of error

Standard bank is the worst bank ever, my experience with them has been the worst so far. I have worked very hard to maintain a good credit record & it has been ruined by standard bank. According to my credit record, I'm 1 month behind on my loan payment & that's not the case. I always make my payments in time to maintain a high score, but once again standard bank has failed me, by allowing incorrect information to reflect on my credit record. This needs to be rectified as soon as possible.