Debit cards or vouchers. Alternatively, you can visit the Air Asia offices but ticket price varies from online price.

some travel agent help ppl to book the ticket... i think airasia office accept cash payment too oh? u dun have maybank, rhb bank or public bank online account mei?

well, at least its all included in
still if u need water, they'll give u anytime.
instead of buying a small bottle of mineral water which finishes quite fast,
esp on long hour flights

just my 2 cents 
no matter what airasia or MAS also no water allowed after the custom.
after that u can buy ur own mineral water else where.

if im not mistaken, u can buy meals in the airplane as well.
but pre book cheaper.

if go london, better take MAS la.
if u sit airasia,
also quite suffering.
as their seats not very wide.

wont la.
dont worry.

why you want to call them?
they prefer you deal anything in their website