How is it possible to use a service you never had?

I have received a number of phone calls with regards to ***. A lady from a collection agency has been calling me for over a year now and I have forwarded all related emails with regards to this account.<br> <br> I sent Telkom an email a month before i moved house to alert them that I am vacating the premises and gave them my the new address. No one responded and I went to the Boulders branch and made the request. I was told the line would be moved to the new house. After a couple of weeks without the line being installed I called Telkom and they told me that my area doesn't have coverage.<br> <br> I then decided not to pursue the matter due to the lack of network coverage and I didn't close the account as Telkom also knew the line was inactive. I then started receiving phone calls from Telkom demanding that I pay them an outstanding amount for the line. I fail to understand why I would have an outstanding amount if I didn't use the service and according to them there is no network coverage in my area, so why would I pay for something I didn't use which Telkom also know based on our conversations and the number of emails I sent to them which they don't respond to. Whats my recourse here?