Vodacom Cancellation Terrible!

I have tried on 4 occasions to call the cancellation number (***) to get my current number cancelled and put onto Pre-Paid or Month to Month but all that has happened is that my contract has been renewed somehow and I've been put on the RED Flexi 70 contract which i don't want to be on. Every time i call i get a different answer and this is frustrating, i need my number to be put onto Pre-Paid as i am Immigrating and don't need a contract. I need this out ASAP