Never available to assist clients

I have been trying to get through to Fnb personal loans department to make a new payment arrangement on my personal loan which is in arrears and I spend more time on hold than anything. I am on hold always in excess of 20 minutes never speaking to anyone to make my arrangements and this is the last available option to get through to someone. Because if I don't do this you debit my account take 60% of my salary and leave me and my sons destitute due to your lack of customer service availability.