Vodacom upgrades and sales misleading their costumers

Their sales department are ********, they upgrade your contract without your permission, I have had a dispute lodged against it but still no contact has been made to me about any resolutions, how is a contract upgraded to 36 months anyway? It's not the first time.. At the start of my contract I was debited for the entire worth of my device, it's been a horrible relationship with vodacom and never again will I be taking up any new business with them again.