They sell a different (tourist SIM card) at the airport. Once your one month subscription ends, you will have worse choices than a normal AIS SIM card. If it’s no emergency, I would buy a SIM card in the city. But ask for a normal one. Not sure they sell tourist SIM cards in the city as well.
I am in a similar situation but applied for a elite since I am 42. I came to Thailand in December 2022 with an visa exemption 45 + 30 days, flight to Vietnam, came back with an Tourist visa 60 + 30 and that is ending on June 11th. My Elite Visa will take 2 more months I am sure. So you saying a border run is a safe option to get 30 + 30? Do I need to show a flight ticket out? Any recommendations for a agency in Bangkok who are trustable?
Yes they asked me for a flight ticket from Germany to Thailand. But in theory I could sent them an onward ticket from Germany to Thailand once I am out of Thailand no? I doubt they check it I am really in Germany.