Need a proper installer to fix an aircon purchased and installer in Feb.

I to have had **** service and faulty aircons installed, I purchased 2 units, less than a month later.the 18000BTU was not cooling down, after many calls the guy who installed the units.Keanu van Vuuren finally came out and there was a problem with the copper piping, also bent also leaking. They fixed the problem and 2 weeks later the unit was not working again. When you call Jet Air to take them on about there installers they are quick to pass the buk and blame the installer, again I am struggling to get ahold of Keanu van Vuuren, the guy doesnt pick up his phone, nor does he return any calls. So I am stuck with a 18000BTU bought in Feb that isnt working. How do I go about sorting this out. I spent almost R16000 on a unit for our lounge and a unit for the baby room. I want people to know that this guy takes peoples money , does the initial installation and then when the something goes wrong you need to lick his ass to come out again. And Jet Air doesn't want to hear my complaints either even though its there accredited installers