How to cancel a Telkom land line account

My mother lives in an old age home in the Strand and my sister and I are trying to cancel her Telkom land line, because she does not use the phone anymore. We are sending emails since March 2015 to Telkom to cancel the land line / account. We even got a reference number - Reference number SM86075.<br> It is May 2015 and Telkom are still billing my mother's account. This is *******.<br> No one has contact us of answer on our emails since we received the reference number. <br> How long does it take for Telkom to answer / cancel an account of a paying customer?<br>