Interest charged for late debit order payment.

I am not happy that I was charged R36,36 interest on the 12th of October as shown in my recent statement (attached) because of a late debit order that I did have control of. I called Customer Services on the 20th (last week Friday) and I was told that the interest was charged because the debit order date was on the weekend and the debit order could only take place on the 2nd of October which was a Monday. After seeing my statement for another account with another organization I realized that they actually make provision for debit order dates that occur over weekends, they even send out SMSs prior to the month end to alert me that the debit order date for my account is on a weekend and ask me if I want the debit order to take place earlier. R36,36 is not a lot of money but for me being charged for something I did have control of is very bad service, I do not control the calender and there was money in my account for the debit order. Markham should have a plan in place for this like other companies if it values us customers because we choose to pay our accounts by debit order because of the convenience and not to be charged unnecessary interest.