You can only access some parts of FTP webpage, due to government restrictions. Amongst other, you are unable to download the program.
You need to get somebody to download it for you, and then either mail it to you, or upload it to some other site, where you can get it.
If you're talking about lobby freezing when entering the right password and refusing any other password : it's not specific to Thailand, got the same problem here in France.
Sent a mail to Fulltilt, and they replied the best way they can : the typical draft explaining how to reset my password.... what a waste of braincells there in their support department.