Dealer cancellation and wrong billing

Dear Cell C , never have I been so disappointed. I took a contract with you last month , a dealer cancellation was done and a reactivation was done because there was mistake with the first activation . A month later I am being harassed for a R7000 bill that I have to pay . Why am I being billed for this ? you nearly debited my whole salary and no one cares . I have called several times and have reference numbers . Nobody has called me back but all I get is harrasment calls . Please check this reference number *** .