Disappearing data

<p>I have over the past few months noticed a discrepency between my own data usage vs the data usage reporting by Vodacom (via the app). Yesterday I finally got proof. I installed a wireless network through a 3rd party yesterday with uncapped internet. Late afternoon I checked my data balance on my phone which was 173mb. I switched off my mobile data and comnected to my new wifi. I took a screenshot of the app report. This morning first thing I again checked my balance via the app and it shows I have 0mb available. How on earth is this possible. How can my cell data deplete overnight whilst my mobile data was switched off??? This is pure ****************. I sincerely hope Vodacom reacts to this post as I need some answers.</p>