Debit Order Not Stopped.... Over R9000 taken

Telkom have been debiting my account for over a year after I have stopped my line. I have gone in the stores MULTIPLE TIMES!!!!!!! and they still taking my money....THIS IS THEFT. They have promised that it would be stopped but still it is taken. The only next step is to take LEGAL ACTION because I am not sure what else to do. Beyond disgusting. This is a ******** act. They have taken over R9000.