Poor response service and wrong information

I have been a customer on a contract over 8+ years. I got called several times to upgrade. Over a month ago, I took the call and the guy offered me a sim only contract for R179 p/m over 24 months. As per the call I asked if the same instalment will continue and from when I will pay et which I was assured R179 p/m and a once off R150. Last month over R600 were taken from my account. Since I have spoken to the Customer care no feedback just a invoice. I have indicated listen to the call recording when I was upgrading and no feedback.