Outrageous Data Charges - S3-9JW26-63K6D

As we approach the end of October I still have not received an invoice or statement as I should have at the begining of October to advise what my bill is and how much will be debited. Imagine my horror when I went online to check and saw a bill approximately R5,000 more than I usually pay. When I called in to enquire I was told that it is data related. When I get sms's from Vodacom to say my data is finished or getting finished I immediately purchase more so I do not understand how this happened. I was told by the gentleman that I spoke to that those sms's are a courtesy and that I cannot rely on them. I was told that he would log my query and someone would get back to me within 7 days. This call happened on the 16th? I also requested that he put a block on my line so that it was not opened because I was unable to do it online, I note that this also has not been done! Can someone get back to me straight away as I was assured this would be addressed before the debit goes off. I know from experience how difficult it is to get my money back from Vodacom when they make mistakes!