Most institutions require that you apply for the WUE rate BEFORE you begin classes. You can contact the admissions office to see if it is possible, but it is highly unlikely that they will award the WUE tuition retroactively. In addition, make sure that if you were awarded the WUE discounted rate that you have it in writing from your enrolling institution.
Online education enrollment has continued to grow according to the new report, Digital Learning Compass: Digital Education Enrollment Report 2017. The overall enrollment in higher education, however, has fallen in the past three years.