Close my account

I tried to close my existing account with Telkom several times before.no luck. I have mailed then the required paperwork, contacted them several times requesting them to stop billing me and close my account. I even went so far as to stop the debit order but found that Telkom only keep on billing me and now deduct double the amount because I'm in arrears. I have written emails but they are very unsupportive. I urgently need them to stop billing me and close my account. I requested the account to be stopped in November Last year when I gave notice but since then They kept on taking money from my account. Will they reimburse me? I don't think so. Please HELP!!!