No feedback or response while being overcharged!

I have been continually incorrectly and over charged on my Vodacom Data device, when there was supposed to be an account limit put on the contract. I was never supposed to pay more than R350, yet was recently debited over R1000. After confirming that there was an irregularity on my account, a service request was logged and I was supposed to receive feedback on the issue within 48 hours. I have still heard nothing a week later. When I phone Vodacom they cannot give me any information and say that they are experiencing delays - convenient that my account is still being debited, but they are unable to rectify the issue. Unacceptable ****************!