There’s different ways to get in touch with your rep. One of these is to use the students-only space. This is a special section of moodle, that no staff has access to, and your rep checks regularly. You can post in the forum and wait for a reply. Some reps even publish their contact details in these spaces, so you might be able to even email them.
Another way to find out who is your rep is to check with your department. They might have emailed you their details, or they might be available on a noticeboard. You can also email a member of staff in your department, and they might be able to help.
Finally, you can also find out who your rep is by asking the students’ union. You can contact us by emailing email@example.com - please send us details of your department and year of study. We endeavour to reply within two working days.