This is how the problem manifests itself now: - When I picked up the car from dealer two days ago at the border the AC was not at first ice-cold, but after a short while it got ice-cold. - I drove for 90 minutes to my home in Dubai. Underway, the AC had uneven performance: it went from ice-cold to a bit warmer after about 45 minutes, then back to ice-cold, then again warming - and then stayed warmer until I reached home. - This morning I drove the car to work: the AC was not cooling at all, the temperature was the same as the outside air. - I started the car again 3 hours later, and the same problem persists.

lost most of it;s freon

Vent selections are sometimes powered by vacuum, and fail-safe to the defroster position when the flow is disrupted.

several issues can cause this problem.
1st. not enough air circulating the evaporator coil meaning dirt filters or obstruction.
2nd. low refrigerant charge.
3rd. the out side tempurature maybe to cold, some units don't funtion well in cold climites.

If you turn on your AC on one day and nothing happens, you may be dealing with a major component failure. Your vehicle's AC system consists of a compressor, condenser, evaporator, expansion valve, a series of tubes and several fans/blowers. If either one of these components fails to do their job, it may result an entire system failure. For example, if the evaporator blower motor burns out, you will get little to no airflow through the vents.
Most modern vehicles also have safety mechanisms that may prevent a component from engaging if the pressure is low in the system due to a refrigerant leak. Refrigerant can leak for many reasons, including undone welds, loose connections, corrosion, physical damage from road debris, etc. Look for oily stains underneath your car, as they may indicate a leak. If you suspect a refrigerant leak, take your car to General Automotive. We will test the pressure and use special dyes to pinpoint the leak.
Warm Air is Coming Out Instead of Cold As you get in your car and turn on your AC, you probably expect it to be blowing hot air for the first minute or two until the system cycles through enough to cool it. But what if the air never gets cold ? Or maybe it it gets cooler, but not cold enough ? No, your car didn't get confused and turned on heat by accident. There is likely a problem with your condenser.
A condenser's job in a vehicle is to cool the warm refrigerant that was used to make the air cold in the evaporator. A condenser has coils and a fan to push the air through the coils and thus cool the refrigerant. If the condenser coils get dirty or clogged, or if the fan fails, the refrigerant won't be cooled completely, so the air will come out warm. It's best to take your vehicle to an experienced AC Repair professional to troubleshoot this problem if you don't know your way around under the hood.
Cold Air Blows Intermittently So you went for a road trip or a long drive, and after 30 minutes of driving realized that your AC suddenly stopped working or switched to blowing warm air. The cold air returns shortly, and the cycle repeats itself for as long as you are driving. What's wrong with your car?
Intermittent cooling is often caused by the components of your vehicle's AC system freezing up. Typically an iced over evaporator is the culprit. An evaporator covered in ice can't cool the air, so you would have to wait until the ice melts, which is why the cold air eventually returns. There may be numerous issues causing the icing-from a dirty cabin air filter to a blocked evaporator drain or an overcharged system. Look for puddles of water under your car-this could be a sign of a freezing problem.

it may be that the clutch on the A/C compressor is faulty & sometimes it doesn't engage or it could be a wire is loose or a loose connector plug, next time it blows hot air when it should be cold lift the hood & make sure that the clutch on the A/C is engaged ......hope this helps......cheers.

Check the magnetic clutch is engaged on front of a/c pump, have the motor running, a/c on and fan on high, if the centre hub is static the pump in not switched on, this can happen when the gas pressure gets low.

Isolate the thermostat sensor. Hold it with your hand and see if it comes on and stays on. If so, replace the thermostat.

make sure the metal bar is in the down position

No. check this post from right here.
http://www.fixya.com/support/t245665-samsung_rs2556_refrigerator_side_not

Question: was the fridge running when you went to pick it up ?
Was it already on ?
My thinking is that you have the ice build up problem too and that it never thawed. If you unplug it, thawing could take days. Seriously. If you take the inside panel off and get some heat on it
only an hour or so.
You have the exact same model I do, and it works good, just designed poorly. It needs a drain hole on that condensor.
And your fan probably is fine. Do not spend $500.

Your cooling unit is shot, I suggest. Most likely, you've lost the R341 refrigerant. Norcold, so they can sell you another cooling unit at $500+, does not make these little fridges with a service port so you can recharge the system. Same with Dometic. Solution is to spend, again, $500+ for a new sealed unit that will fail in relatively short order (I'm on my second in five years) or buy a better refrigerator. I'm opting for a new fridge this go around (Vitrifrigo). Vitrifrigo has the needed service port.