Mazda 2 won't start
 

I have a 2008 Mazda 2. A few weeks ago the it began having start issues, taking 3,4,5 then progressively more turns (20) of the key to start. I booked it into Mazda for a week later, but before my appointment, my husband was trying to go somewhere, managed to start the car after 10-15 turns of the key, and then the engine died. He called NRMA roadside assistance, who said it was a key issue - he thought the keys had to be recalibrated by Mazda, so towed it to Mazda Service Department. They have had it for a week now and are telling me the PCM needs replacing, and a new one will cost $2400 shipped from Japan, and they are still trying to track a second-hand one down, without success.

Is there anyway I can be sure it really is a PCM problem? I don't trust the dealership very much because I had words with the manager when they said I didn't have an appointment and wouldn't look at it for a week, and now the mechanic/manager won't talk to me directly on the phone - he goes through his receptionist, and they went straight to the PCM.

What questions should I ask to verify they have checked everything? Can the PCM be reset rather than replaced? Is there anything else I can do to avoid paying $2400 + labour costs?