Once a course is FULL, each course owner is notified, and they can choose whether they want to open the course up to additional students. Sometimes it can take days or weeks to re-open a course. In some cases, the course owner may choose to turn the course off rather than allowing additional enrollments.
A course or university contact is generally listed on the Details page for each course. You may contact them if you choose. If a contact isn't listed or you do not receive a response, please reach out to your University Administrator.