Dissapointed in Telkoms service

I am so dissapointed in telkoms bad service Ive been with them for so long in April I emailed them to cancel my business line, Ive sent all supporting documents, phoned every week all the agents tell me is that it will get cancelled......i must forward email I did that and today the The 6th of July i still got a R3000 rand account from telkom my line is still active after 3months. How is this possible??? Im really dissapointed in the service and I dont know what else to do to get the line cancelled, all they tell me is they will credit the account but thats not the point i want the line cancelld as in yesterday!!!!!!!!!!!!