Air Asia are a 'nickle and dime' gouger airline. Their point to point, pay for extras model is super annoying, but they are a great airline. They have brought the price point down for air travel within the region, and provide a great service.
The problem I have with their model is that their sliding scale pricing can force charges well over the price that full service airlines do when the plane is sold to 85% or more. So an Air Asia ticket can cost much more than a full service ticket, especially for next/same day travel.
They continue to offer fares of 50-75% off of others' on many routes where the occupancy load is low. Find those seats and Air Asia CANNOT BE BEAT.
Glad to hear that you got to change your tickets saad. As you said, you got what you paid for!... tickets at a cheap price... And were able to change the ticket too! Sweet!