Yes, you are entitled to a full refund if you withdraw from a course before the census date. (Note: international student withdrawing from a whole program may not be entitled to a full refund.) The tuition fees paid will automatically be credited to your account and will remain there ready to pay your next lot of tuition fees.
However, if you would like a refund immediately, email studentfinance.Enrolment@unisa.edu.au to put in the request. They can pay the refund via cheque or transfer directly to an Australian Bank account. Please give details in the email regarding how you would like the payment and also any instructions such as BSB and account number.