Refund Requrst for overpayment of study fees

I registered with the Unisa for second semester studies.And I appliesd for funding from my employer. However due to late releases of 1st semester results my employer could not pay the fees on due date because of the admin involved in releasing the funds. I decided to pay the minimum amount in order to study 2nd semester. My employer than paid the amount I qualified for, which resulted in my total fees to be overpaid. I then followed the procedures and requested for refund. 2 months down the line, I have had nothing but automated responses from them. When tried calling to do a follow up the phone just rings endlessly. I would appreciate it if someone can get back to me and tell me what to do in order to get my money back. My student number is ********** 3.