Fnb ruined my credit score falsely

FNB is ignoring me after they wrongly listed me as arrears for 90and 120 days and has negatively affected my credit score, I need to know what step to follow to get justice in this regards . FNB temp loan which was paid successfully shows that it's in arrears for many month, I am beyond angry as this has drastically reduced my score , affected my employment and FN B must rectify and erase history from my record with all credit bureaus. I will not rest until u rectify this, I will take every necessary step possible . Why do u find pleasure in ruining a black woman