hazardous living environment

My wife and I were looking for a property to rent so we called a property agency called STATUS-MARK to help us find a place . They said they had a unit available at Glenerin on Jan Smuts Ave in Craighall which we went to view and liked. the unit was vacant and clean. So we paid their deposit and submitted the contract which was approved. A day or 2 later we got a call to say that the property was no longer available and that there another unit available at a different place called Sonrad also on Jan Smuts Ave in Craighall. We then went to view but couldn't as there were tenants occupying the unit. We were then assured by the agent (Natasha Jacobs, Kyle Saunders STATUS-MARK agents and Ishmael the caretaker that the tenants would be vacated on the 30th of September and that the unit would be clean and ready for us to move in which was not the case. The unit was a mess the was no keys to lock the bedroom door leading to the balcony. the unit was hazardous to my wife who has a chronic illness (Asthma). We were being overwhelmed by an influx of ****roaches in our food in the living areas, the ceiling, wardrobes, couches, bathroom and especially in bed. blocked drains leaking toilet etc