Airtime and data dissappearing

<p>My mom is a 75 year old pensioner and has a J1, Samsung phone. She cant afford a contract and is on pay as you go. She buys R110 airtime monthly (15th of the month) .</p> <p> </p> <p>We have wi-fi at home, and my mom uses here phone only when connected to wi-fi.</p> <p> </p> <p>2 Months ago we saw data and airtime disappear. Called Vodacom customer care because even when she was connected to our wifi, mobile data would be deducted. Phone was set to data switched off while connected to wifi.</p> <p> </p> <p>On 24 Dec 2016 we called Vodacom again as data and airtime disappeared again. We started to keep record of the data and airtime few times daily</p> <p> </p> <p>At</p> <p>24 Dec 10:10 there was R347.77 and 100 MB - just bought.</p> <p>24 Dec 21:50 R345.77 and 99.58 MB. R2 missing for no reason and didnt make a call, and half a meg missing.</p> <p> </p> <p>25 Dec 10:40 R344.03 and 99.53 MB</p> <p>25 Dec 13:34 R344.03 and 84.98 MB. 15 meg missing.</p> <p> </p> <p>26 Dec 6:25 R344.03 and 80.02 MB</p> <p>27 Dec 5:45 only 26.44 MB and didnt use phone during the night</p> <p>27 Dec 8:45 R331.99 and 0.97 MB</p> <p>27 Dec 8:54 R262.44 and 0.00 MB (while talking to Vodacom customer care)</p> <p> </p> <p>Airtime is depleted within days and during these days while my Mom was connected to wifi for most of the time. Vodacom can not explain this. Airtime also vanishing into thin air.</p> <p> </p> <p>Phone is also set to do system / app updates when connected to wifi.</p> <p> </p> <p>We are very unhappy with the situation, and want this sorted out. We tried everthing to stop the depletion of data and airtime, but nothing works.</p> <p> </p>