I got climate control on my 172 it works great, I press the demist button and it does its job very quickly.
Sounds like yours may be faulty, the AC system has a sensor in the pipes that will shut off the AC if the pressure of the gas in the pipes drops to low.
An easy test to do is to open your bonnet, start the car up and turn the AC on, then have a listen under the bonnet , you should hear the cooling fan cutting in and out every few seconds and also you may notice a click as well(This is the AC compressor running).
If you dont hear anything then you may have lost the gas again. The most common cause of this is usually a stone in the AC condensor rad, have a look at the botton part of your front bumper, you will see a it then, then get a light and check for a stone stuck in it.
If you have a stone then you will need a new condensor rad and a regas.