Telkom not cancelling my contract!!!!!!

Last year September I took out a contract with Telkom for an ADSL line package. After waiting 3months the line was never installed, however I was receiving statements from Telkom. I have phoned them numerous times first to follow up on the installation and then to cancel the contract as it became clear to me the installation was not going to happen and NO ONE could assist me. I then logged a cancellation on the website and one of their agents contacted me back and assured me the contract was cancelled. However their debit order still went off my account in December and January. I then tried to contact Telkom again to rectify this on their billing but again NO OBE was able assist me, so I had my bank reverse their debit orders. They now have the audacity to threaten me with Legal action for not paying the bill of a service I NEVER used!!!! My advice to everyone....Stay away from Telkom they are pathetic!!!