After cancellation still being billed

I have on a number of occasions have asked to cancel my wireless telkom service as I can not receive a good enough signal at my home. A technician came to my to test the wireless signal and confirmed that it is not strong enough. Here is the case numbers from telkom ***1 and ***7. And still getting billed for a service I cant use or have not bring using since it was delivered to me on the 2nd July 2015. This is very unsatisfactory, as now I am paying for 2 services, 1 for my adsl line and 1 for my so called wireless connection. What do I need to do for telkom to refund my monies and cancel this useless wireless broadband internet. <br>