Hisense portable aircon

Bout a 12000 btu portable aircon from makro , there had a few options but I choose hisense because I have other appliances thats the same brand and worked well , unfortunately this doesn't perform well at all , it blows very slow and my fan blows more air than this aircon , I have a standard size room and the room doesn't get cool , I have to switch my fan on instead , very disappointed