The refund of unused portion of tuition, fees and other charges for veteran's or eligible persons who fail to enter a course, withdraw or discontinue prior to completion of program will be made for all amounts paid which exceed the approximate pro-rate portion of the total charges that the length of the completed portion of the course bears to the total length of the course. The tuition adjustment will be determined on the ratio of the number of days or hours of instruction completed by the student to the total number of instruction completed by the student to the total number of instructional days or hours in case.