Cell phone provider

For the past 8 years I had numerous contracts with Vodacom, the last one was a 3 year contract. 1 year into the contract Voda started removing more money from my account than they should (That is *****). Many frustrating calls in 18 months I managed to get it sorted out. I decided that when my contract was over I would not stay with Vodacom as I prefer not to deal with companies that are *****ulent. Two months before the contract was to end I call an notified Vodacom that would not be renewing my contact, I was to I needto call back in a month which I did and received an sms to confirm this on the 22 Nov @ 14:02. In January this year Vodacom continued to try and take money out of my account which I instructed to bank to reverse. Now on almost a daily basis I have received treating calls from Vodacom threatening to Black list me if I don’t pay R1400 and some change. (That is exhaustion). How come companies like VODACOM have the power to commit ***** and Exhaustion and and get away with it, we as consumers have none.