Owner refusing to pay my rental deposit of R6206.00

I wish to lodge a complaint about Rose Eedes properties, i sent my notice on the 11th of March 2020 as i was moving to another province and due to my lease agreement i was suppose to get someone to take over my lease as it was only expiring end of July 2020. I advertised the room and found a potential tenant but they decided to inflate the rental and the person could not take the place because i advertised the room for the amount i signed for. The landlord is refusing to pay my 2 months deposit and now i am receiving letters from their lawyers claiming that i am owing them R10.400. I vacated the place in March and i have been communicating with Rose regarding my deposit ( landlord) and all these attempts were in vein. When i wanted to find out when is she paying my deposit she said i should write an email saying i am cancelling my lease due to the Corona Virus so that she can claim from the insurance. I refused to write the letter as my notice was sent before the lock down. Please help me to get my 2 months deposit from these people as i am currently at home without income.