Should be able to easily get copies of your parents birth /marriage certificate/ house book to prove you were born in Thailand, to a Thai parent and entitled to Thai Nationality.
I'm not sure I really want to give them my business. The incompetent agent so far has sent me someone else's quote, and doesn't know that they will have a suitable product available after 1st November. Call me a cynic but I think they were chasing the comission on 100k policy knowing full well that there was 50K product on the horizon. That's my opinion anyway. 🙂