Go to the immigration office that serves the area where your TM30 has you registered and ask them when, and with what documentation, you can apply for your extension.

@James *******

OP is in Bangkok now.

Anonymous participant you officially entered the country in Samui as that’s where you went through immigration.

Anonymous participant You get one stamp from the first immigration officer you see. If your flight is to Bangkok, you get it there. If you transit in Bangkok on one ticket and stay in the transit area in that airport then transfer to Samui you get it there like you did before. After that you’re in the country and travelling domestically is the same as it is everywhere else. You don’t see immigration. No one checks your visa. You’re free to travel around. It’s not North Korea.

What kind of problems do you imagine you will have taking domestic flights? Thailand is a free country. No one examines your visa or asks you why you're travelling inside the country. You don't get entry stamps when you go to different parts of the country. The entry referred to on an entry stamp is entry to the country itself, not different airports inside the country when travelling domestically.

Pattaya agents can help you

I understand that, but there's not really much else you can do is there. It sounds like it's the latter stages of the process anyway, so upload the docs and cross your fingers.

They want all pages of your passport to show you’re still in Vietnam.

Send them what they asked for and you should be ok.

It’s your visa. Print it and show it to the immigration officer

You need paperwork from the place you’re going to be using. It already needs to have been paid for and they have to send you specific documents for your DTV application. It can’t just be a general interest you have in unspecified activities.

You need to have chosen what the activity is before you apply for the visa