FNB deducting money for no reason?

I have been noticing a deduction on my account with refrerence RCP Fee For Pls (with a long code). I have tried querying this before but had for luck from the bank. These deductions continued happening. After googling the refference I came across the terms and conditions of the revolving loan from FNB, and it stated that an admin fee will be payable if late payment or no payment is made. I do have a revolving loan with FNB and the fee for the loan to be deducted from my account via a standing debit order. This always happens on the last day of the month and there is always money in my account for it to go off, yet I pay this late pay admin fee. I checked my bank statements from when I got the loan (January 2014), until now. And this has been happening every month since I got the loan. On my bank statements it shows this late pay admin fee gets debited and directly after that the fee for the loan gets debited. For almost two and a half years I have been paying this fee when according to your terms and conditions I should not be. I know every month it is not a big amount but after two and a half years, it is a hefty amount. I find it unacceptable and would appreciate some feedback ASAP to get these errors rectified and the money to be credited back to my account.