Prepaid Data

For the past 5 days, I have to load 100mb of data and before the end of the its all depleted. On Sat I called Vodacom, and I was advised to go onto my settings to switch off some of the applications and the consultant took me through step by step, he then assured me that I won't have a problem again. The very same Saturday i'll loaded data and it was still depleted, Sunday i'll loaded as well and hardly 5minutes there after I received an sms to say it was depleted. Could someone please provide an explanation of what is happening to our data, I have been asking people that uses Vodacom and we all are complaining about the same issue. It now feels that I am only working for data purchase.

Funny enough, I have never qualified for any advance before and this morning I had the option to choose from R5 to R10, why now?.

Awaiting your soonest reply!!!!!