"ไม่สามารถดําเนินการซื้อให้เสร็จสมบูรณ์ได้"

Your screenshot tells you what you have to do i.e. contact iTunes Support. If you haven't already done as instructed and contacted them you should do so (these are user forums, not iTunes Support) :

- go to http://www.apple.com/support/itunes/ww

- click on your country's flag (the country where you are, and which is therefore the country on your account)

- click on Contact Support towards the top right

- click on Get Help under 'Talk To Us'