@Lloyd *******
My school refused to give cancellation letter and I don’t understand why. They have to give me cancellation letter so that I can go to the immigration and cancel my visa, right?
Is there any problem if I leave Thailand without cancelling my visa? Will I know if I have overstayed or not when passing through airport immigration? If I overstay, then I can pay the fine and leave at the airport?
I don’t have any plan to get long-term visa in Thailand except for tourist purpose.