Cheap Air Ticket

This year i have reserved many air tickets.
those is not mine. just friend of mine.

1. Early October -- Nagoya to Phnom Penh --- Ok
2.Early December --Nagoya to Phnom Penh --- Ok
3. Mid December -- Nagoya to Sydney --Ok
4. Mid December -- Nagoya to Sydney --Canceled
5.Mid December -- Nagoya to Phnom Penh --Ok
6. Early December -- Tokyo to Soeul -- NG

it is good if i can go to Cambodia myself.