Vodacom worst service ever

I am totally disappointed in Vodacom's service. I was due for an upgrade in June 2020, but I cancelled my contract on 09/05/2020 through the call centre due to the fact that there was no deals that was affordable to me. I was informed that my last payment date was end June 2020. Then I got a bill early July for payment end July. I contacted Vodacom's cancelations department to find out why they are still billing me, because I cancelled, but the agent told me that they have no record of the cancelation, and they need to investigate. The agent asked me whg I cancelled and I advised her that it is due to affordability. As he then checked her system an told me that she has a great deal for me which will accommodate my affordability. (IPhone SE Flexi 175). I spesifically asked the agent if they had stock of this phone, and she assured me that they have, and that she can confirm it on her system. It all sounded good to me, so I agreed. She advised me that delivery will take place within 5 - 7 days. A few days later I contacted the call centre to find out what is happening, because I haven't heard or received anything from them. The agent then told me that she can see the upgrade but they do not have stock of that phone. I told her that the agent that did the upgrade assured me that there is stock. After this call, I emailed Vodacom and told them to cancel my contract as they sold me a phone under false pretenses. I got a automatic reply back that they got my email. Once again I had to phone the call centre again after a week of no response from Vodacom. This call centre agent wrote a review on my account to her manager with my whole story, and advised me that the manager will contact me. 4 days later, and still no communication what so ever from Vodacom. If I could rate no stars in the rating I would have. Very disappointed in Vodacom, as I have been a customer for over 15 years