Vodacom upgrade fiasco

Someone phoned me from Vodacom to assist with an upgrade. It turns out what they confirmed is not what I got. It also turns out that I received a call from a " branch" and not Vodacom directly - I was not made aware of this. My new line is supposed to be top up but they made it contract. The number of minutes confirmed is way more than what I'm supposed to be getting. 800 minutes vs R65 airtine confirmed. Due to their error, I'm now paying way more than I should be paying. And no one wants to fix it. I'm being sent pillar to post trying to fix this. I've even been asked to pay a fee to correct the error. Why should I pay, the error was not my fault! It's been 3 months. When I call the call centre I'm told to go to the branch I did the upgrade at to fix it yet I didn't visit a branch. No one wants to help me. I'm now paying double the agreed amount and I don't even understand why. Whatever you do, don't choose Vodacom.