Except the oil consortium decided against the ATR after insisting it be used. Only to discover it was much more expensive to operate when compared to the ATP, and then reverted back to the ATP.
As for reliability on the ATP, the dispatch figures tell the truth. The ATP is no more unreliable than any other aircraft, it just has a bad press.
Many of the delays associated with this contract were down to tech choppers or wx, but the ATP was often made to be the scapegoat.