I went to immigration in Jomtien to ask about a DTV visa extension. From what I can tell, they were not super happy about it. One nasty lady at the information desk outright lied to me that they don't do DTV extensions and I need to exit and reenter. Of course, I didn't buy this BS and went to ask the information desk "boss" (the older lady sitting on the left). After a few shouts between them she told me that I can extend it but need to come within the last month of the current 6 month stamp.