Bad customer service from FNB

On my credit report it shows that an amount of R2234 has not been paid since September 2019 and i informed FNB about it that its having a negative rating on my credit report and even FNB acknoledge that there is no such an amount owened to them i ask them many times to contact credit burea to have it removed but with only a responce that i must contact this dept then i contact them then oh no you must contact that dept.I am fedup and need help pleaae