Intec Colleges poor service

Good day, I am currently a student at intec College. When I enrolled I paid for my tuition and all exams fees upfront. As payment was made upfront I was given a discount. However I received a call from the intec's accounts department stating that I have an outstanding balance. I called the college several times to rectify this but they have still not gotten back to me. Intec is now withholding my results, which is needed for my prospective employer. I am appalled by the service received by intec.