Unisa has messed up my life

I was enrolled at Unisa (University of South Africa) and was funded by NSFAS, however, when I tried to register for third year I was told that I owe over R30k and when I told them that I am funded by NSFAS they told me to tell NSFAS to pay, I wrote to NSFAS, NSFAS rep**** and told me that Unisa made course code errors and Unisa was only supposed to fix those course code errors, I sent them that *** to Unisa, they only fixed a third of those errors and NSFAS paid that third, I only made every effort to follow up writing to every relevant *** but never even received a response from department heads, thinking that they understand it's their (Unisa) error, I got funded where I now work and I tried to register, but Unisa took that money and paid my supposed debt and I couldn't study, I started following them up in 2022 and even now, I still owe Unisa, I am unable to finish my studies because of Unisa's error and the most hurtful thing is writing to department heads only for them not to even send automated responses.

Now I do not know where to start because till now I am not in a better place financially to settle that debt and continue studying, I need help