Vodacom should account for data disapearence.

I am disapointed at how my data disapears and no one can really tell me why. I bought 1G data on the 5th of February in the evening, the whole day i used wifi at work on the 6th. I opened mobile data after 5, only went on watsapp, at 7 Pm my data was depleted and my airtime was also depleted. I bought data again at 8 pm, another 1 gig, now not only did my data disapear again,they cannot account were my recharge for last night went. I recharged through the app that connect to my bank. I have proof that money was taken through my bank and a successfull recharge message was sent from Vodacom.... the agent said she will send R50 airtime, i am still waiting even now. She then said she will escalate my querry for investigation... i am fruatrated i can not call or communicate cause i am scared of buyin more data as no one accounts for data that disapears. I cant not loose R300 over of data i did not even use.