The worse debit order policy!

How is it possible for a bank you trust with your hard earned money not being able to do a debit order reversal on your account? What is the purpose of the “Debi check” feature if it doesn’t notify you that a company is trying to debit your account?? FNB I’m utterly disappointed in your service. I would simply like to have the rights to reverse/stop a debit order should I not know the company which is trying to debit my account.