AIRTIME THEFT

I purchased 1gig valid for a day data on my pre-prepaid number ***,the data was supposed to have depleted at 23:59:99 as per vodacom's sms.to my suprise this morning i received messages.I bought another R25.00 airtime this morning in order to buy data,once again vodacom took my airtime,i just bought another R20.00 to buy data again vodacom took my airtime.This is day light ******* and i want my airtime back.Vodacom never explained this to me,the consultant advised i must switch my mobile data off,who switches off the mobile data when you constantly use the data.No one explained this to me,the consultant said its the system is like that and there's nothing she can do.I need vodacom to re-imburse my airtime back.