Bad customer service

My bond is with Sa Homeloans. I am not in arrears and also not in financial difficulty. All I want to do is to change my debit order date from the 25th of the month to the 1st of the month as you can do with insurance companies etc. I have been in contact with them from the beginning of Nov and just not winning. When my debit order bounced on 25 Nov I made an EFT with my instalment before the end of Nov. I emailed them again to state that my monies come in on or just before the end of each month so I need to change my debit order date. Now if I change my change my pay date to the 1st they expect me to pay a double instalment on the 1st. I am stuck with this double instalment because thing. This means they work backwards.They referred me now to Loss Control Dept and they came back to me to say that they will suspend my debit order for Dec which means I can EFT my instalment but will reinstate my debit order again on 25 Jan. They just refuse to understand. They are not accommodating or assisting. They just bombard you with 1 liner emails and you can never speak to someone in management. Their service are bad and very unprifessional. They just don't care. I do not know what to do next. Do I need to see a lawyer?