Disappointed in fnb

I am not happy with fnb. I bank with them and I took out a personal loan with them. They could see when my salary gets paid into my account each month but they still made the debit order for my person loan to be deducted from my account a day before my salary gets paid into my account. When I phone fnb Personal loan department to change the debit order date they state that my installment a month will be more and that's unacceptable. Why must I pay for an error made by the bank when I took out the loan the consultant did not ask me when the debit order should go off and I bank with fnb so they could see when my salary get deposited into my account every month. I phone on the 1 April and spoke to precious and I ask her to let a TL contact me to sort this out, no TL has contacted me back yet and today when I called to speak to a TL they just kept me holding. Please help get this sorted without my installment being increased as I cannot afford it. I'm very disappointed in the bank and I will not suggest that anyone take out a personal loan with FNB.