Horrible Experience from Vodacom's Billing Department

I am experiencing absolute horror from Vodacom's billing department. I have taken a cellphone contract with Vodacom in January 2022 with a fixed monthly premium. My premium has since gone up twice! When I enquired about this I was told that it was communicated to me that the premium will increase. I asked for a copy of my signed contract which they were unable to provide me as there is no signed contract. I asked for the recording of when I took the contract with vodacom which they are unable to provide me. They told me that they will provide me with my contract document WHICH IS NOT SIGNED and which I haven't received from them. I was told that Vodacom is allowed to increase premiums as they see fit without consent from customers (keep in mind that I took a fixed premium contract). They also added some items to my billing as they wanted without my consent which also increased my premium. I am absolutely and completely disgusted with Vodacom and would NEVER recommend them to anyone!!