UNACCOUNTED FOR ADVANCES

My mother uses a Vodacom sim and lately every time she loads airtime the airtime is deducted from her account. She has no recurring subscription but upon further investigation on her phone I noticed that she owes airtime advance of R280.00 She doesn't even know how to request an airtime advance!!! Looking at the historic advances it shows that she she requested over ten R10 advances on the 28th of November? Does Vodacom even allow a client to request so many advances in a day???? This is an elderly woman!!! She loaded R250.00 of the airtime recently which got deducted and she STILL has an outstanding amount of R280.00 in airtime advance??? WOW!!!! Not being able to speak to a consultant is even frustrating because Tobi doesn't give you an option to question these advances? This is REALLY frustrating especially because my mother doesn't want to change her number but has to endure the frustration of repaying advances done with her number when she hasn't even made calls or used the airtime.