Agent won’t pay back security deposit!

I entered into a lease agreement with Bianca Properties in March 2017, stayed at the place for almost 3 years. I paid R8000 deposit back in 2017 and moved out end of January 2020, it’s June 2020 in 2 days and I have not received my deposit back. Michel Tshepe has switched off her phone and won’t reply my emails. When I call the other employee at the agent they also can’t get a hold of Michel. I had a good stay at their property and I didn’t think they would treat me this way. I am so disappointed, to say the least! I really wouldn’t recommend anyone renting from them because of this awful treatment I’m getting from them.