VODACOM not a nice to deal with

I have 2contracts with them and expired on October 11 and yet they still bill me for it, i have been in contact with them numerous times since July about this as they kept calling me about this contract that was about to expire and when I told them that I'm not continuing with a contract I only want it to be converted to a prepaid and they assured me via email as well as by calling me promising that that request would be done. and we at the end of October and they billed me again full amount which is now against what they promised me. and if I go to the nearest store to complain, they give me a number to call and I have sent their customer services email after email and yet no response so I am fed up with them, I don't know how to deal with these idiots going forward. they have sent me a ref number as a confirmation that my contract will be cancelled in one of the emails that we've been sending back and forth between me and them: ***-KA0W was sent on the 8th October. on Friday 23rd Aug a person named Sibabalo Njengele wrote to me via email confirming that my contract expires and he followed that up by calling me to confirm the above that is after I had emailed them the previous day. on the 8th oct, I reminded them that this contract is not to be renewed and deduction should be adjusted accordingly and they confirmed but never actioned. a person by the name of Mawaka Ngudle called me & emailed me on the 24th September advising that my contract on this other number is indeed and will be cancelled as per my request but i'm surprised why they are deduction a full amount again for the end of October, they never adjusted the monthly premiums to reflect that only one contract is in force these idiots, i'm so so angry at them right now, it is a nightmare to deal with VODACOM to get them to cancel they refused totally to let go of my money and its irritating to having to call over and over again for such a simple thing I wouldn't advise anyone to take up contract with these *********** bunch of ******.....