Having read many threads on this very subject, seems the front pads are much too hard for the discs, hence the quick wear rate.
I would suggest anyone facing the same problems to go for after market kit, use softer pads to avoid disc wear, Eurocar Parts will be able to help.
My IS250 Auto will be due the third year service in January 11, 23.000 miles at present, will wait and see what Lexus Newcastle says at the time.