Telkom billing ineptitude

Thanks to Telkom's inability to contact us on any platform we are now receiving threatening phone calls and sms's from VVM Lawyers. We cancelled our Telkom account on 8 November 2018, without Telkom informing us that there was still an amount outstanding. We have not received a single bill from Telkom since then, not a phone call, sms, nothing, in spite of Telkom having all that information on their system. When we log onto our account on Telkom's website we are told there are no bills outstanding! Why should we be penalised for Telkom's ineptitude?? I REFUSE to talk to the lawyers as it is TELKOM's fault, not mine! Telkom is the one who failed to inform us of monies outstanding and whose system is so faulty that we cannot even see that we are overdue.