可以选SingPost offline payments
http://www.jetstar.com/sg/en/help/articles/payment-options
Paying by 7-Eleven and SingPost offline payments
You can pay for your booking at SingPost outlets or 7-Eleven stores in Singapore.
No Booking and Service Fee is payable if you select SingPost as the method to complete and pay for your booking. A Booking and Service Fee applies for payments made at 7-Eleven in Singapore.