Internet and Cancellation issues

My ADSL service was replaced due to cable theft in the area and Telkom delivered a Telephone and a Mobile router. The telephone worked well but the router for internet connectivity never worked. The Technician who delivered the Router said we must give it 24 Hrs to be activated but still it didn't work so I called the Call Center and they told me that the Modem is not synchronizing, they suggested that I take the Modem to the store because if they send a Technician and it is found that the fault is with me I'll be Charged about R 300.

On Saturday, 02 June 2018, I went to the store to get the Modem configured, the store Technician told me that the new service will never work as the are a number of customers who come to the shop complaining about the new modems. So he advised that i cancel the fixed line service (at the store) and i did as advised. He then told me to complete the service i need to call the Call centre in order for them to come and collect the Modem and Telephone. I'm not sure whether the cancellation will be effected.

When i called the Call Center i was sent from Pillar to post with no department willing to assist and now i'm frustrated that i will be billed for a service that I'm not using.

Why did Telkom recommend a service where non of their Technician get it to work.