Real Estate Agent Not Responding to Request for a Refund of the Tenant's Rental Deposit

For the last two years I rented my house in Cape Town through PentaProp, which is owned by Arie Korf. The tenant has recently moved out but she cannot get hold of the Estate Agent, Arie Korf. He has stopped responding to our emails and whatsapp messages.

This is a very frustrating time as the tenant is now demanding the rental deposit from me, even though Pentaprop is the one that sourced this specific tenant and all the monies were paid into their account.

Please help !!!