Damelin doesn’t want to give me my money back

I’m a former student at Damelin City College in Durban. Unfortunately I overpaid went to collect my statement and saw I have R5700 that I overpaid with. Since 2016 I’ve been trying to get my money but unfortunately I can’t I went there and they told me I must study something I don’t wanna study anything there all I want is my money back. It’s been years!!!! They asked for a slip which I don’t have. And me overpaying was they fault cause that’s the money they said they want. Now they making excuses and offering me programs from they’re college I just want my money back