FNB debit order

I'm a fnb client I love the bank and I don't wanna change to any bank last month there's a debit order that keeps debiting on my account which I don't know the company or where is it from and why are they debiting I called fnb to reverse and block the debit order their unable to help I went to branch still got no help I keep calling and sending emails but I keep on getting nothing everytime when I called their keep on referring me to a different department Im very disappointed about their recent service