Deposit not refunded

I stayed at Rider Haggard flat number 602 from March/April 2005 until we cancelled the flat in December 2007. We sent a fax to a lady by the name of Alwana who was dealing with building. We moved out in December 2007. We have never been refunded our deposit back. We tried countless times to go to the huurkoor office in sunnyside to see Alwana but we could not find and and we were later told she had moved offices. She claimed that she never got our letter to cancel the flat. It is just sad that till today we have not received our deposit back,