In this article, the writer says your 30-day visa can be extended at the immigration office before you have your passport stamped.
I've never been to an airport. How is it possible to have your visa extended before having your passport stamped, which I assume happens when you enter the country with no choice but to have your passport stamped?
Can you still extend your visa if your passport gets stamped? And what if you already have a visa? Do you have to take the entry visa too?
Sorry if my questions are all over the place.