Thanks guys, we did the test to bypass the cutout switch and it still didn't get cold so it is definately a low gas problem and the old mate at the aircon place had some special light and glasses that shows where the gas leaked out and it was coming out of the front of the compressor but nowhere else!
I understand why they would replace the reciever drier but can't for the life of me work out why it would cost $2500 to fix. That's just highway robbery to me!
Cheers.....................Pete!