Refund on over charging on my billing

I have been with Vodacom for 2 decades and suddenly when I went to a Vodacom shop on the 11/10/2020 to upgrade my phone and device. I was told that my number has been upgraded in June. I was not aware of this. I am really disappointed with the service. I asked to speak to a consultant I called from my wife's phone no one could assist. They said they will call back to no avail up until now I have not received any response, I want an answer on who upgraded my phone and was not advised accordingly. Please This is service is unprofessional. I am going to stop my debit order if I don't any response by today. I am paying for services I am not using.