The code for my iTunes University course is not working.

I have created a course in iTunes University for teachers at my school. The code to enroll has suddenly stopped working. I copied the course, but now I have students in two different courses which technically are the same. The problem...I am still adding posts. Bottom line is I need for the original course code to work. I contacted iTunes help and was given directions on how to enroll! We already know how to enroll...if the code doesn't work...well then...we cannot enroll in the class. Please help.