UNAUTHORISED DEBIT ORDER

I’ve never had or opened a contract with VODACOM, UPON CHECKING MY CREDIT SCORE I SEE VODACOM AS ONE MY SERVICE PROVIDER AND AM PUZZLED BECAUSE IVE NEVER EVEN ACCEPTED A MANDATE FROM THEM. WHAT SERVICES AM I BEING CHARGED FOR, EVERY TIME I CALL THEIR CUSTOMER CARE AM TOLD SOMEONE WILL CALL ME OR ITS BEEN ESCALATED, THIS HAS BEEN HAPPENING FOR MONTHS. ITS RUINING MY CREDIT SCORE BECAUSE SOMETIMES WHEN THEY DEBIT I HAVE NO FUNDS AND AM BEING CHARGED UNPAID BANKING FEES. CAN I HAVE SOMEONE LOOK INTO IT BEFORE WE GO THE LEGAL WAY BECAUSE AM ABOUT FED UP WITH VODACOM