FNB Temp Loan

I took a temp loan of R5000 on the 1st June, as money I was expecting had not come in yet, and I wanted it to cover my debit orders. My son paid me back an amount of R1500 for the DSTV and Telkom that he uses, but it in my name, on the 4th June. Today, the 5th June, FNB debited my account with the full amount that was sitting there, as a repayment against the 30 day loan. It does say in the terms and conditions that they will deduct from any deposit that gets paid into the bank, but I seriously thought it would be after the 30 day period and the loan was not yet paid. 5 days after taking the loan, they start withdrawing it again. Seriously? Will they refund me the amount they debited for giving me the loan? Of course not. If I was a bad debt I can understand, but I have been with FNB for a number of years, and have clean record with them. Shocking.