Unfair penalties, poor management

I don’t know if Telkom understands the essential elements of a CONTRACT. You give your consensus to be debited on the 25th of every month, No Telkom goes to debit you a day before your agreed date. I went to make available for the 26th of December in anticipation of being debited on the 27th or 28th, to my surprise, I had a returned debit order that went off on a unauthorised date the 24th, on the 27th because I don’t want my credit score to be affected at all, I went to the Boardwalk store and they directed me to make an easy payment which I did on the same day. Now I get my monthly statement, my bill which is R200.70 more I called the call centre they advise it’s due to the debit order that returned. A debit order that went off a day BEFORE my agreed date. A date I never opted into. I asked to speak to Dimakatso Makganto’ s manager Neo , he was too busy to take my call, I ask for his name he refused to give it , I asked for a call reference , to my absolute shock TelkomSA does have reference numbers for so-called recorded calls wow… so Pathetic, I need someone to contact me with regards to how the terms of a written contact can be changed , without written nor verbal consent , without both parties agreeing to it. I have heard that with Telkom it will be a miracle if this gets rectified and I receive my callback from Neo. I WILL NOT PAY A PENALTY FEE FOR A DEBIT ORDER THAT WENT OFF BEFORE MY AGREED DATE! Please show me how this goes to treating your customers fairly