Supersurf is 800MB per day for prepaid and will reset in midnight.
This may be able to ease your confusion.
Both statements above states almost the same thought. The data cap doesn't mean that it is all you got from your SuperSurf subscription, but it just states that once the cap was reached, you can still use your SuperSurf subscription but with a slower speed. Also, as to what bodlat25 mentioned, it will refresh by 12MN.
Hope this helps.