My non B-Visa trip to Savannakhet was sabotaged when my school didn’t provide an approval letter from the MOE which is apparently a requirement. If I get a 60 day tourist visa from the Thai consulate can my school convert it to a Non-B at immigration in Bangkok? Or does it have to be a 30 day visa on arrival by flying in? My car is parked at the border in Mukdahan so flying isn’t really an option.