Access to Leeds portal wont work - what should I do

I need to register for the access to Leeds module by Wednesday and I have been trying to do it constantly since firming my choice but I keep logging in and getting a page which says 'sorry the server has been brought down for maintenance'

I have emailed the admissions team at the university and they have been useless!! I have been doing this on a mac but have tried different browsers (firefox, explorer and safari) I always get the same result... Has anyone else had this problem and do you have any advice on what I should do?