Recently booked a ticket from KL to Hanoi, received an email "Confirmation" from Airtickets24.com. On arrival at Hanoi airport for travel to KL, Vietnam Airlines would not let my fiancé fly as they said the Airtickets24.com confirmation was not valid and had been cancelled. Cost us a one way ticket as a replacement so my fiancé could fly.
As for "Customer Service" of Airticket24.com, save your breath for the porridge, an absolute joke. Rude, arrogant and officious, not interested at all in hearing about or resolving the problem they created.
KEEP AWAY!