BAD BAD ATTITUDE, UNHELPFUL, IMCOMPETANT

I HAVE LOGGED NUMEROUS CALLS WITH VODACOM, FIRST ABOUT 5GB DATA GOING MISSING, AND INCORRECT BILLING, DATA REPLACED AS A ONCE OFF COURTESY, WITH NO EXPLANATION AS TO WHY, AND THE BILLING REMAINS INCORRECT, LOG A CALL, GET A CALL, CALL GET CLOSED AS IT IS NOT THERE DEPARTMENT, BUT YOU CANNOT GET TO SPEAK TO THE CORRECT DEPARTMENT. THEY ARE IN THE "BACK OFFICE" AND NOT REACHABLE BY PHONE, THE WILL "CALL YOU" AND THAT DOESN'T HAPPEN. ONE THING PROMISED ON RENEWAL OF THE CONTRACT, ANOTHER HAPPENS WITH BILLING, AND TO TOP IT ALL, THEY MAKE IT IMPOSSIBLE TO CANCEL!!! PATHETIC SERVICE AND STAFF!!!!!