Worst agent, won’t pay back deposit

I’m really disappointed. I’ve been renting under this agent since 2019 and I decided to move now in December. Flat owner advised me to contact Burmain to get my deposit money but they are no avail. I’ve tried contacting them, emails but they don’t pick up their phone nor respond to my email. They owe me R5100 deposit money and today it’s the 24th, 24 days since I moved out. Flat owned claims she can’t get hold of them either