Vodacom has no idea what they are doing

This is getting rediculous. 3 years back I took out a contract with Autopage cellular, which closed shop in 2016 and transfered my account to vodacom. Due to vodacom's accounts department it happened that I started to skip payments and they barred my number. I went in to vodaworld customer care department to make arrangements to pay the amount. Long story short, they never deducted the amounts on the dates requested. I refused to go back to vodaworld as it takes a good morning and to phone their accounts department was like banging your head on a wall. By December 2017, a company that does debt collecting phoned me on behalf of Vodacom, and we made the arrangements to pay of the outstanding amount to get my name of the blacklist. The amounts was paid in full and my contract was closed by June 2018. My name was taken of the blacklist and I was assured I owe vodacom nothing anymore and my contract was cancelled. Now at the end of November 2018, I get another call from a debt collecting company claiming I now owe R800 still for the handset...... what the heck. I havent even been using it, and for 6 months nobody said anything. Why was I not informed of this hidden charge when they phoned me end of november 2017 in the first place? We could have sorted this out then. Why is it every year December that vodacom comes with their debt collectors to milk you for money? Now if I agree to pay this outstanding amount (which does not make any sense), what will they come up with next year November. I will probanly then have to pay for the cell phone charger. VODACOM. YOU CAN HAVE YOUR PHONE. I DONT WANT IT ANYMORE ANYWAY. please sort this out as I am really not impressed. There was nothing said when the debt collectors phoned me in the first place and your customer care is worthless. Try to phone your accounts department or your customer care department through your switchboard and share your experience..... I would rather deal with your debt collectors as they seem to want my money. But enough is enough. It cant carry on like this.