Do not ever upgrade over the phone with Vodacom

I upgraded 6 months ago via Vodacom's tele agents. The contract I was offered was 50 minutes, which was not enough, so they gave me 75 (which did not exist). Eventually I upgraded again, but was overcharged, so started a 6-month journey to rectify this, but it is still not correct. I have several mails from 2 people, *** & *** stating the correct amount. This was also promised over the phone, but still the problem is not solved. So, the 18th of September I logged my previous call, a guy name Lance phoned me back from the web team twice, saying the second time they want me to move to another contract yet again. They already moved me to another contract but did not stick to their word regarding the price. So, I am going to pay less, but also get less. Someone from the sales team were supposed to call me. Nobody called me back yet. The 2 people mentioned above refuses to answer my mails anymore. They say it is an accounting problem. So, to anyone out there, if you want to pay less, just phone Vodacom's accounting department and say they overcharge you, apparently, they will listen to you and comply. Amazing!