Intec refusing to refund for overpayment

When I was studying with intec I had overpaid my account by R900 for which they promised to refund that in July 2018. I sent all the documentation for the refund but 6 months later I have not received no refund from intec. All I get is empty promises, please if anyone know what steps I can take to get intec to refund me I would appreciate it. ********** 0671