Double debit order without my authorization or permission

I was called by Mthetheleli Mkhobeni on the 25th of February asking about my car payment. I explained that money had gone in at midnight and it looks like the debit order is still in process. They should wait for it to be processed as I bank with Nedbank. Only to find out that he authorised another debit order without my consent. Now I have been debited twice and I must wait 7 days for MFC to fix the issue. On whose authority was Mthetheleli working on and why is it that someone can just do as they please in my account? This is nonsense and an infringement of my right to consent!!!