Can't seem to get them to cancel my contract

Having a contract with Vodacom has resulted in a lot of pain and to be honest, disgust regarding their retentions. According to the website and the mobile app, my contract ended on 29 September 2017. Having considered cancelling and porting to pre-paid to get actual benefits (from another supplier) I contacted them to cancel the contract on 7 September which I was told would be processed and my contract will end at the end of the month. I understand that there is a 1 month notice period and expected my contract to actually end on the 7th of October... However, much to my lack of surprise, my phone is currently STILL working and I am being billed by Vodacom. 11th of September I contacted and spoke to Zolile who then explains that the website is wrong and my contract will only be cancelled on 16 October... I am not genius, but surely that sounds like 9 days longer than the 1 month notice period? So trying to rationalise with myself, I think if it ends half way through the month, then I should get half of what I normally pay for and be billed accordingly... Wait, another "Why am I surprised at ******* service" moment? My data and minutes went from 400 to 150... again, my math tells me that if I am being billed for half the month, I should get half of the contract I was originally paying for?

So as I write this, I am sitting on 45 minutes on hold for the retentions department so that I can find out why on earth I am so silly to think that if I ask for something and get told it's done that I should actually expect it to be done... especially after I chose the option to talk to retentions and had to register my voice and then got told I would be transferred to someone who would help me with my request to register for voice recognition... for lack of a better term, *** Vodacom? I can not wait for this to be finished so that I NEVER have to deal with Vodacom again!! I never want to spend another cent with a company like this! Following that, I will suggest and insist that everyone I know leaves Vodacom!!!!!