Failure to diagnose the problem

I bought my daughter a U Choose Smart M Package through the Vodacom Store in Bedford Centre plus minus a year ago . My daughter studies and stays in Stellenbosch . My daughter notified me on a regular basis that i need to top up her phone account as she had no voice or data available on her phone . On average this cost me R 1000 per month . ( On top of the monthly contract fee ) On her next visit home we reported the problem to the Vodacom shop in Bedford Centre , they told us that either somebody was hacking into my daughter's account and depleting her funds , or that she was a heavy user or that the phone was leaking data with unecessary data / downloads . The problem continued and was reported to the Vodacom shop in The Neelsie centre in Stellenbosch . The answer given : \ we don't know ""