Unauthorized Debirt order

South African Payment exchange has been debiting my account using my id number, i don't know them and don't know how they got hold of my details, last month they Debited R95 from my account using Ref LUVMORE and my full id number , this month they did the same using RNM Hold, who are these ********** people, my bank gave their contact details the phone just rings with no answer, the people has my account number and full id number someone must investigate them