Very disappointed with Vodacom service

<p>I have a contract with Vodacom and is coming to an end on March and the upgrade was on December, so Vodacom people have been calling me for upgrade and I turned them down that I will upgrade when I am ready but they upgraded my contract without my permission after I have realise i called and they cancelled and second time this month the upgrade was done without my concern again, I have been calling and nothing was done so I don't feel like doing any upgrade since nothing has been done its almost a month end, since I email Vodacom forensics and even did a service request for ***** on my account twice in month. please assist</p>