Nedbank allowed rain to debit without permission

I have had issues with Nedbank before and I gave them another chance for my salary account. They allowed rain 5g to go into my account without a debit order mandate and tell me that because rain has my account humber they can debit. Which is *******. They debited R625 today from my account and this is unacceptable. So anyone can go into my account because they have my account number. That's *****. Rain is not even on my list of debit orders that have been approved. Ni have NO debit orders I pay rain manually on a pay as you go basis. I want my money refunded and I'm not waiting 7 days or completing dispute forms. Rain didn't need to fill out forms to go into my account. That money was for rent and my son's school fees and I want my Nedbank account closed. I'm done with them