Wrong debit order deduction that resulted in a negative impact on my credit profile

My credit card debit order got changed without my knowledge and I got charged a penalty fee and damaged my credit record because of this. When I did my application I specified that my debit order should be on the 20th and they just changed it to the19th without my knowledge. Fnb's call centre is USELESS. Nobody seems to know what they are doing and I was told that the penalties on my name could not be reversed even though it was an error on their side.