Billing problems

So, telkom decided to process a debit on the 24th of the month, then it rejected because there was no enough funds in my account. When, i took out the contract with telkom i told them to process a debit order on the 25th of every month because thats my pay date. I get paid on the 25th of every month even if the 25th falls on the weekend. Telkom is now charging me +-R200 for the debit order that did not go through on the 24th. They processed a debit order again on the 28th and it went through. Now when I phone them they tell me they do not see the debit order they processed on the 28th. I'm not sure what i should do now, because I have lost trust in their billing system. Can this matter be escalated to someone who can get this matter sorted out. I need the penalty to be cleared and a revised statement for August 2018 issued. I thank God i have not yet upgraded my contract as yet. They have never asked me when to debit my account if the 25th falls on a weekend.. I was obviously gonna tell them to debit on the next working day. I have never had problems, only in the month of August 2018. Please correct this asap. I need to decide on an upgrade..