don't have a service but still paying

I called an cancelled my services 6 months ago but still I'm being billed I have even sold the business but still I have a bill I keep calling an getting a promise they will cancel it but they don't I went to Montana an stood for 3 hours because there was only one person to help as the other was on lunch I am tired of been send from pillar to post I don't want to have any services with Telkom I'm going to take my existing business to neotel just cancel the service please I'm not using it an it's 3 lines to be honest Telkom I never thought your service could be so poor