Livid with Vodacom

I bought airtime this morning for R80.. which I then converted into 1G data.. its supposed to last for 7 days. It was depleted within minutes.. I then contacted the call centre... and the consultant did not pick up the transaction.. which was odd because I received messages confirming the airtime bought and the conversation to data.. She couldn't answer that. She them told me it might be my background applications which update automatically..

I told her it's odd that it happens this only because I buy the 1G data every 7 days and it's never happened..why now...

She couldn't answer me.. This is ridiculous.. I feel cheated..