Air Asia — Self Check In

Website:

checkin.airasia.com

I booked a ticket via Air Asia. They had explicitly mentioned on the ticket that Self Check In was free. However, when I tried to check in, I was not able to get any seat of my choice. All the seats are chargeable and it is not possible to change the seat without paying. I tried their customer care many times but the agents were very rude and diverted me to a Terms and Conditions page in Air Asia website. These terms and conditions are not mentioned in the eticket and there is no information or even an note that hidden T&C are mentioned on the website.