Unreachable UNISA

I can not reach any department at UNISA. Not telephonically nor through email. I tried the main campus, I tried the regional centre, I called 8 different telephone numbers frequently from March 2020 to today 19 August 2020. Is is way more than 100 attempts. Not one single answer. I do not know how to sort out my student account. A credit of more that R 25k need to be passed and I have no success.