Unable to access online exam and no feedback from UNISA

The online exam for UNISA is not working. You keep on getting a 403 or 502 error and then when you eventually do get in, the page just hangs. Nothing happens. I tried to email the lecturer and the exam department to inform them of the issue and they have not responded at all. They have not even posted an announcement to note that there is an issue. This is very bad.