Telkom for the lose

Telkom is great until you try to cancel your service. I am moving and need to cancel my line. I have given more than a month's notice via their online portal, been in to the store 4 times (all the staff tells me is they don't do the cancellation and they send an email), sent numerous emails myself (that are ignored every time both by the tech staff and the store staff at Canal Walk). At this point I have 2 choices: pay the phone bill that the new home owner creates on my account or stop the debit order at my bank and risk damaging my credit record. This is highly unfair and I cannot fathom why the staff at Telkom refuse to help me!