Dear Khun Suwannee,
Please find the tentative flight detail in the attached file.
Dits travel service fee 250THB per ticket.
There’s 2 types of tickets.
NON- flexible : change flight/date fee 1000THB. + fare different. No baggage allowance. You can add on 15KGs. = 300THB. per way.
Premium flexi : change flight/date free of charge + fare different. + free baggage allowance & meal.