2 GIG Data runs out in prematurely

The issue relates to an elderly lady who uses her VODACOM 2 GIG data package to check her Emails which she has done for over 4 years. Suddenly in the last 4 months or so, her 2 GIG of data runs out on around the 10th of the month. I am fully aware that there must be something on her machine that unbeknownst to her is using the data. I requested a URL report to try and assist her to find where the data is going with out any luck. Surely as part of customer service, someone from VODACOM technical can assist in getting to the bottom of this situation . Please help to sort this out as sending mails and talking to call centers is not only time consuming, but futile.....not from a lack of trying!!!