Ensure your work has been submitted into the system. We know there are times you submitted your work only to find out later that it wasn't sent at all, or it wasn't sent successfully.
After you submit an assignment or test, a modal window with a tracking information appears. Copy and save this number as proof of your work, and evidence for academic disputes.
You can also receive an email with the tracking information in a text file to keep for your records, if you have a registered email.