I suspect it may be US credit cards that do not accept Cebu Pacific not the other way around. With persistence and random luck I have got it to work. Same goes of Lion Air in Indonesia and a troublesome period with Tiger Airways. Basically persistence and random changing of strategies eventually got the tickets on-line but not in any kind of consistant professional manner. I still say they should just take PayPal if they are to incompetent to set up a working credit card billing system on their own.