Cell C can't get my debit order right

Cell C does not seem to understand customer care. They cannot process an arranged debit order for any other day of the month than the last day. Since I changed my debit order to the 5th of the month (I don't receive a salary, I work for myself) the wheels came off. It is now more than a year that Cell C cannot seem to take the debit order from the correct bank account, or on the right date and because their accounting system cannot accommodate any other day for payment (seems like it), they now say that I am in arrears with a month's payment. Every month they cut my service. Every month I pay. Every month I have to call them to reconnect me. Now I have paid double... and yet, I have to wait for my line to be reconnected. I cannot wait to get out of this contract! I have been a Cell C client for more than 10 Years. All was fine as long as I receive a salary on the 25th of the month. Cell C know what to do with that. It seems that Cell C cannot accommodate the small business owner. They can only work with employees that earn a salary before month end.