R903 out of bundle

<p>I have a 2GB data bundle on my ipad which I never use up so it carries over, this month I therefore had almost 4GB. So I was suprised when I received an sms out of the blue saying I have gone out of bundle to the amount of R903. Why do I only get warned once I have gone out of bundle and once the amount is at R903?? The sms could have alerted me sooner that I am nearly out. I'm still suprised it could have gone out of bubdle since I never use all my data. Also the vodacom app was again out of order earlier when I wanted to check my data balance. I would like to know which date and time I aparently used so much out of bundle data and what the out of bundle rates are.</p>