Vodacom dispute non-response

I cancelled my contract (without early termination) but was anyway charged for half a month, when I ported out straight after the contract was supposed to have been cancelled - despite 2 phone calls to confirm the cancellation and it's date. I logged an invoice dispute on 13 April, and instead of the "3-5" days for someone to send me feedback, I'm still waiting. What *****, debiting my account when unauthorised, and they do nothing to resolve it.