Vodacom is being dishonest, reaping people off

So I have the vodacom router that grants me 60gb. 30GB to use between 12am and 5am. The 30GB to use between 5am and 11:59pm. For the past 4 months the 30GB could not even last to mid month and I have been asking myself what exactly uses the data cause I am at work most of the time and I do not use data intense applications. Interestingly, this month of May I personally monitored the use of the WIFI router and I switched it off most of the time, to my surprise today the data is depleted. I call vodacom to find out what exactly is happening to the data. The lady call center was helpful but what she told me did not make sense. I requested an itemised bill from last month. The bill is not very useful, but at least it shows when the dates and amount of data used on the dates. To my surprise again, data usage was recorded on way after data was depleted on my side . I wonder if there was ghost data on my wifi. So VODACOM, WHY DO YOU INSIST ON REAPING PEOPLE OFF???? THIS IS UNACCEPTABLE.