How long time you have to go there for your appointment? For me for example if I would apply in Germany I have to apply at the embassy in Frankfurt which is still more than 2 hours from my home…?!
That means I should have at least one week for scheduling an appointment…
As Elias replied already, have to go to the NATIONAL IMMIGRATION AGENCY (can find it on Google maps), they will give me a certificate!
I asked the embassy and they said they need this as the stamp could be from anyone (I would not tell them that on the bottom of each page is also the passport number)
A friend of mine applied for a NonB Visa, it did not get approved within 4 weeks, he entered Thailand on a Tourist Visa, than his NonB got approved while he was in Thailand.
He made a boarder run to Myanmar and got his NonB Visa stamped in.