wrong billing and bad customer service

i have a contract with Telkom and i had 3 lines in which one was a laptop, the other was Tabled and the third one is a cellphone. the laptop was expiring in July 2017 then in march 2017i called their pathetic call center to request the line to be suspended until the time for cancellation comes. Then in June 2017 i went to a Telkom shop in forest hill mall and singed a cancellation form. only to find out that the line was not suspended and the cancellation was also not done. I'm still receiving billings for the same line even now. i called the call center again in October after i received the invoice with the billing of R1000 the callcenter said i should open a case and until now nothing has been done when i make a followup i'm being told that the matter will be refereed to the manager and it will be dealt with urgently but that has not being done. i asked for my refunds from July until to date and i did not receive a cent i'm told the line is active. how can i pay for the line that i cancelled in June and that i suspended in March.

Telkom service is pathetic and i want all my money back.