Fnb affecting my credit rating

I recently took out a person loan with FNB with a debit date of 20th as this is my pay date. Ov the past 2 months they have debited my banking account on the 19th being the day before I get my funds attracting unpaid fees from my bank and affecting my credit record.I have called the call center to advise them to change the debit date. <br> They now inform me that if the 20th falls on a weekend they will debit me the Friday before.<br> As much as I am trying to explain that I do not have sufficient funds then they insist I must cater for this as that is what the contract says.<br> What Hogwash. I have requested they cancel my debit order & I will pay manually & told I can't as they will affect my credit record. Damn if I do damn if I don't <br> Again I December the debited me on the 15th despite me stating my debit date is the 20th.<br> What is the point of signing debit date when they process the debit dates as and when they wish. now I have unpaid fees on my account which they don't care about.<br> What is even funny is I am calling to inform them to move my d/o day to at least 3 days after<br> It's true that the service at this bank is going down.<br> Maybe I should call for a legal opinion