Cancelled 4 Months ago

I cancelled my telkom line 4 months ago and I am still being billed. I have phoned telkom at least 3 times a month since then and instead of cancelling my line they have added a new product which i requested before i decided to cancel. I cancelled because they kept giving me issues about adding the product. They have now been charging me for 2 products and the cancellation has still not been processed. I will not pay for a service that I cancelled.