Refund for overpayment not paid

I made a repayment few days after I got paid by them and I overpaid them with R124.55. They updated their system and promised to refund me back my money after 3 business days and now it's the third week but still no money. I emailed them twice reminding them about my refund still nothing. I thought they're the best but as far as I see they're a ****