Impossible to contact university

I have been a Unisa student for many years and have a number of qualifications through them. I have always been very happy with the level of service but not this year. I app**** for a post graduate certificate months ago. I know they have a new admission system which is slowing the application process down but I have sent two separate e-mails regarding my admission with no response. I have also tried the admissions and applications phone numbers on the website [URL Removed] All of these numbers have been engaged for literally days. What is going on UNISA!!!! You need to let students know of the status of their applications. It is literally impossible to get answers, I am very frustrated.