Data Usage on Autopage/MTN account

I check my data usage as I've previously had a large account from Autopage in April. On Sat 15 Aug, my son did research for a school project, I checked the status of the data and there was about 400Megs left. The new data comes in on 17th of the month - with a whopping bill of R4005.69! I immediately raised a dispute with ref 815624 with a Dora and email complaint on 19 Aug. To date, no feedback despite multiple calls to the call centre to ascertain the findings of the \investigation". I made payment based on my previous 'normal' accounts at the end of Aug as I had not received a report of the outcome of my dispute. The account was suspended on 01 Sept . No response to email sent 02 Sept. On 14/15 Sept I tried calling again and was told that the IT dept said I'd \""used the data\"""