Bill in bundle, out bundle, in bundle -- charged R1300; help please

<p>Good day - on my bill I very conciously manage buying data, however on 29 Sept a huge amount was downloaded and billed. I am not sure how this happened, but I am very concious about buying enough data; is there anyway that this mistake can be corrected either from my side or from Vodacom.</p> <p> </p> <p>Any assistance would be appreciated, since the amount charged is so much.</p>