Debit order dates

I went the a FNB bank 2 weeks ago to change my debit order dates.On my credit card and my loans acount.The gentleman that help me. Said I had to call the 2 department.On the phone.I spend an hour on the phone wait for the loans department to answer and they did not so we cut the call and 45mins waiting for the credit card department to answer and again no joy.Ihave wasted R150 just on airtime trying to get a hold of them.and All I need is my dates to change from the 15th to the 25th of every month