Debit oder on incorrect date

Good day, I am still waiting for Telkom to replay to my complaint Account Re: Telkom Invoices and Statements - *** they tried to debit on the 30th August which is not what I have signed for on my contract the debit should be on last day of each month, when I call unfortunately the staff is been rude telling me that I have to make an EFT payment. Awaiting someone to contract me thus is my 2nd complaint this year. My contract ***