1. the Thai embassy where you are flying from. In your case, thai embassy from Cambodia
2. The rules each thai embassy gave. Which they clearly indicate STV can only be applicable for Cambodian nationals and permanent residents residing in Cambodia.
Unfortunately, many people with similar issues like you were not able to fly to Thailand too. 😞
Thanks. I decided to take a visit to the Smart Visa office personally. Turned out they are more into it once they see you physically. Seems like I'll be able to get this settled by next week.
I’ve submitted mine a few weeks back and was concerned since I am under amnesty. I had a single non-b visa previously but expired in May. The SMART visa told me that it is not necessary for me to apply for an extension since I am still under amnesty and I will get a reply next week.
But if this is not approved, I will have to request for a letter from the embassy.
Think in your case you will have to try asking your embassy now since the date is after 26th?