R2636.78 owing and R2569 debit order went through

I owed R2636.78 to FNB on a Personal Loan for which the original loan amount was R60,000. I have operated this loan with FNB since 3 March 2011. I enquired with FNB as to whether the full amount owing would be put through on the agreed debit order day and FNB affirmed that this would be the case yet on the debit order date FNB put through a debit order of R2569 and it expects me to pay a CPP Premium of R177 and Fees of R49 thus a total of R226 on a balance of R67.78. Why could FNB not just debit the full debt outstanding and close-up the account. I'd two other Personal Loans of R20k each which I paid up in the normal course of the life of the loans. I have never missed any payment on any one of the three loans and this is the kind of thank you I get from FNB for doing business with them. I am disgusted and it is not about the money that I have to pay up unnecessarily but as a matter of principle.