incorrect billing and NO SERVICE on queries theret

ON 11/5 CALLED THEIR OFFICES RE extra for data and MMS to the value of R50.90. I keep a very close eye on my data usage by dialing *111# every single day and if I see I only have about 30MB left I immediately buy data, which I did twice last month, as per the once-off data bundles reflected on my account. However, I sometimes incorrectly receive sms' from VODACOM telling me I have run out of data or nearly out of airtime when that is nowhere near the case, as I immediately check and usually have more than sufficient data, whereas the Vodacom sms states the opposite. I have called in before to advise an agent of this and they telephonically clarified that I did in fact still have data and today the agent confirmed that I do still have airtime, although I received an sms from THEM ON 10/5 saying I had used 90% of my airtime, this too is incorrect as I still had 65 minutes left, which she clarified, so there seems to be an error on their side and I am being charged therefor. I requested a deduction of the R50.90 on my account for data usage, when I DEFINITELY did not run out of data bundles at any time. Consultant unhelpful and still no response to my repeated emails.