That was back on June 2 in Doha in a purchase deal with Airbus as opposed to the lease option above:
The airline said it will buy 13 Airbus A320neo (new engine option) international planes and another A320 to join its domestic fleet. Among the international planes are at least three A321neos.
The first A321neo is due in late 2017 with the remainder of the aircraft delivered at intervals through until 2019.
The additional A320 for the domestic fleet will be delivered early next year.