Cebu Pacificīs online booking is simply a roulette game hit or miss.
And it takes great patience until you finally can make a booking.

I have flown a couple of times on 5J and booking was always difficult (and i have German Credit cards)
Highest score was usually with VISA.

If you want to book C.P. it takes pure luck ! Reservations hotline is most of the time "busy" - best to try call them between 2am and 4am Philippine Time.

For the peace of mind you may book with Air Asia to Clark (50mi north of Manila) and i can promise you this booking will work !!!

If you intend to travel domestic in the Philippines iīd recommend looking at www.airphils.com or www.zestair.com !