Impossible to cancel

I requested my line to be cancelled at the beginning of January, then again sometime the middle of January, then again on 30 January, but still I am being billed R600!? Please can you help sort out this problem? I refuse to contact your call centre because the people on the other end are useless and I refuse to hold for 30min just to be told I need to hold another 30min in order to speak to someone who then again can't help me. All I want is for my line and complete account to be cancelled. I am also being invoiced for another account I apparently have and apparently owe you R958???