Unauthorized debit order

I had a debit from my account from MaxLaw which I didn't even mandate for the debit order,therefore the branches I've been to their branches(Tembisa plaza and Birchacres) twice and yet they can't help. They are telling me they can't solve the issue because the money cannot be reversible. I am irritated because how can I trust them with my money where else they can't solve issues which I didn't authorize?