Unauthorised debit order

My account was debited an amount of R89.00 on 31July 2015. I don't even know what this company does and how they got hold of my banking details. I haven't spoken to anyone from their company regarding taking up a service with them, Unacceptable behaviour! <br> <br> When I phoned them they apologised and said they will look into it within 48hrs.<br>