Data Dispute with no feedback

Last month (Sept) I got a debit order of 3265.49 on my account. I queried this as I usually get charged 460-500 for my monthly usage. The itemised billings displayed data usage after midnight on a number of occasions (when I am asleep). I obviously disputed that, and the consultant promised that I will get feedback within 7-14 days. It is now 16 days later, and I received a call from Customer care to say that I am being charged 230.30 for this dispute on my data (which was never explained to me and I never agreed on). I called the Accounts department back, and they cant retrieve any of my information or dispute on the system. Vodacom has my money and I need to know exactly what it is for. This is poor, unacceptable service, and I have waited long enough for feedback.