No proof or justification of declined application

I app**** for a rental, was declined for reason that I cannot afford the place. On which grounds can Estate Agencies dictate on what people can survive on. After all of my rent and expenses there would have still been money left over but yet I was still declined on basis that the amount of the rental must be exactly a 3rd of my net income. This Estate Agent rule is now becoming ridiculous because for example if a person has a Net income of R40000 and want to rent or buy a place for R20000 and expenses are R10000, there would be R10000 left over as pocket money. So my question is where would the justification be that a person cannot afford it.<br> Furthermore there was no proof sent to me that indicates facts that I cannot afford the place. I asked the agent about it and he said they have to comply with the NCR rules, I tried complaining to the EAAB and the NCR but their response was that they do not regulate this. Thus it means that Estate Agents are being \selective"about who can get which place and bypassing 1st come 1st serve - ergo: **************"""