The Worst Machiavellian Company in SA

I relocated out of SA in January 2016 and back in November 2015, I duly informed Telkom of my impending location (some months heads-up). They advised me to fill out a cancellation form which I duly did and emailed with a returned confirmation. My house is empty and no one is using any Telkom services there. But as many other people have experienced, Telkom kept billing me up to today (31st October 2017)!! Some months back, I asked my bank (Standard Bank) if they can please cancel my debit order with Telkom, but they said they can't. All they have been doing is after Telkom bills and takes the direct debit, I formally write to have it reversed. You can imagine the stress of checking every month and remembering to go through this paper work monthly, in the midst of every other thing going on in one's life. Anyway, through this, I have managed not to pay Telkom for the last 3 months, for a service I'm not using and that was cancelled way back in 2015! So now, Telkom have sent a debt collection agent on me to recover R1600.33. Where is the CPA and other official consumer protection agencies? Telkom is behaving like an arrogant bully with total disregard to customer service. Worst mistake I made was agreeing to pay by Direct Debit. I'm going to start a Social Media campaign informing Telkom customers never to agree to Debit Order arrangement and to change provider if possible.