tardis's post in Used capacity was marked as the answer
Are you sure it's saying you've only used 3 MB? I can't read Dutch (?) but in English, that page shows me how much space I have remaining for the month. Not how much I've actually used. It looks like it says you have 2.8 MB remaining and your limit resets in 20 days.
Here's mine in English. 990 MB remaining not used.