Vodacom trying to ***** my money

I phoned Vodacom Around the second week of May 2018 to cancel my contract with them. The lady on the phone told me that I could not cancel my contract as yet because it was only ending at the end of June although my online profile and the app on my phone showed that it was ending at the end of May. I proceeded to tel her that it was fine and that she should put in for cancellation at end of June 2018. Around the first week of June I thought that I would check on them to make sure that the cancellation request was done and nope it was never done so I told the gentleman on the phone to please put it in and that he could go back on the telephone recordings and will hear that I phoned in May for the cancellation. When I phoned back on Monday the 2nd of July to find out why i was still on the air the gentleman told me that my contract was still not cancelled and that the previous requests was done but cancelled right after they were put through. He cancelled my contract with immediate effect and that I could move to the new service provider. Now this is how Vodacom *****s money from the clients. I got a account for July 2018 although I was not on there network any more and the explanation I got from them was that I only cancelled my contract on the 2nd of July and that no notice was given to them for the cancellation so that's why I am still liable for the account. I explained to the consultant that this was not the case and that I attempted to cancel on 2 previous occasions but that fell on def ears. I will not settle the account for July as I feel that Vodacom is trying to ***** from me. They can go back on the recordings and will find that I have tried more than once to cancel the contract with more than enough notice so please go check the recordings and you will see that I gave you enough notice. Cancel the invoice because I will not pay it for services not rendered and for you being ***********.