Overcharged and don't care

I was contacted telephonically to upgrade 2 of my numbers more than a month ago as they were both due for an upgrade. I told the consultant that i would upgrade but later (within 1 hour) called them back and advised them to cancel both upgrades, now i have been billed for upgrades which were supposed to be cancelled. I have spoken to a consultant on friday but they are unable to help me. I was told somebody would contact me but until now nobody has even bothered calling me. Pathetic service vodacom!<br> <br> Why am i being overcharged.