airtime deduction

I recharged my account with R30 voucher and then it was deducted by something,then i call the customer care line first spoke to miriam who told me she cant help because it doesn't reflect on her system what happened on my airtime.Then i call again and spoke to Dikeledi who told me Data took my airtime and it doesn't show what kind of smart data that took it..So like seriously how am i suppose to solve this problem if my service provider is telling me there's nothing they can do to assist, while i have R30 airtime that just went.Just let me know what to do.