How to submit proof for education discount?

I recieved an email saying adobe was unable to approve my education discount due to no proof being submitted..

they have provided a link to the adobe support portal online, and what to do:

"To respond to this update or review your case history, log in to the Adobe Support Portal online and look for your case number in the "recent activity" section. Should you need to send us additional information, you can do so by opening the case and submitting your update."

when I go here there is no 'recent activity' section, and alos the 'case' sections display "no cases found"

I have 7 days to submit proof, but how am I meant to sumbit it! I have tried googling but no success..

thanks.