Can Cell C please get this right

So, a week or so ago I reported Cell C overbilling my account by a few thousand Rands. Yes, they have responded and have credited my account for the overcharge. May I however add, no apology from them. They are doing me favour by crediting my account!!! I also asked in my last Hello Peter report and telephonically that they must cancell this contract with immediate effect as this happened to me last year October as well. They without authorisation from the customer open the line. Yesterday and today I receive threatening e-mails that if I dont deposit the monthly subscription fee of R287.00 in 2 days I will be handed over. Seriousely Cell C... No1, you made the error, No2 I did request immediat cancellation of the contract and No3 if the account is paid in arreares surely you can now make arrangments for a 2nd debit to go off my account at a later date for the subscription amount. Threatening a customer when it was your billing error and to go back to my previous statement there hasnt even been an apology.<br> <br> PLEASE WITH TEARS IN MY EYES CANCEL THIS CONTRACT I DONT UNDER ANY CIRCUMSTANCES WANT TO DO BUSINESS WITH CELL C EVER AGAIN!!!!!