Attempted debit order

I have a debit order with Telkom for my contract. I actually prefer paying online for it so I normally pay before my payment date. I paid on the 24/01/2020 however there was an attempt to debit my account and due to insufficient funds I had gotten charged an extra R100 reversal fee from my bank. When I phoned Telkom they told me nothing could be done as I needed to pay 10 days early. Why do I need to be inconvenienced. This is the first month I am having this issue. There are other people who complained of being double debited