Unauthorized debits

I visited the capitec branch Maponya mall to be assisted with a loan, the service I got from the gentleman that assisted was great. I only realized today that the is a company thats debiting money from my account without my consent, we called the company and I was told that they could have captured my banking details by error on their clients profile . I am concerned about the safety of my account because I thought that for my account to be debited by a third party I have to give authorization but I am surprised it seems as if that's not the case. I am thinking of moving to another bank because I don't think my money is secure with my current bank. I was advised by the consultant that they can not stop the debits from their side, it's sad because I am being debited for something that I didn't sign up for.