INTERNET BILLING

I AM SO FURIOUS AT CELL C. I HAD A MODEM CONTRACT WITH CELL C, AND IN THE FIRST FEW MONTHS HAD PROBLEMS WITH IT. I WENT NUMEROUS TIMES TO THE MALL TO SORT OUT THE PROBLEMS. AFTERWARDS I DECIDED THAT SEEING THAT THE MODEM IS GIVING ME PROBLEMS, I JUST WANTED TO COMPLETE THE CONTRACT. I NEVER USED IT FOR ALMOST A YEAR AND A HALF, AND LOW AND BEHOLD TO MY SURPRISE WHEN R527,00 WAS DEDUCTED FROM MY ACCOUNT ON THE 25 FEB AND THEY TRY TO DEDUCT ANOTHER R187,00. WHEN ENQUIRING ABOUT THE DEDUCTION, I WAS TOLD THAT IT IS INTERNET BILLING. WHAT INTERNET BILLING!!! THE MODEM HAS BEEN BROKEN FOR A YEAR AND A HALF AND WE CANNOT USE IT. WHERE DO THEY GET THAT BILL??? I ASKED FOR CUSTOMER CARE TO SEND ME A STATEMENT TO KNW WHATS HAPPENING, AND IM STILL WAITING. I AM SO DISSAPOINTED IN CELL C. I WILL NEVER HAVE A CONTRACT WITH THEM EVER AGAIN. I CANCELLED THE CONTRACT AND PLACED A STOP ORDER ON THAT ACC, BUT WHAT ELSE CAN I DO TO RESOLVE THIS PROBLEM. I WANNA TAKE THE MODEM TO CELL C AND SHOW THEM THAT THAT PIECE OF **** DOESNT WORK. AAAAHHH!!!!!!!!!!