My aircon wouldn't blow cold last year. Took it to the dealers who diagnosed a faulty fan motor which required the dashboard to be removed to replace the motor.
Predictably once the motor was changed it still wasn't cold, so they changed the compressor which sorted the problem. All of this was done under warranty so it didn't cost me anything.
Just out of interest, I enquired about the cost when I collected the car. The service guy was telling me the figures for various parts and then labour rates. We gave up once we got to £1000!! They had my car for a week and supplied me with a courtesy car while this was being done.
Can't fault my local dealer so far (fingers crossed!)