@Rey ************
you don't get a visa on arrival and you don't get a tourist visa at the border,
I thought they told you to go BUY a tourist visa at the thai consulate in Phnom Penh or another country so you'd get stamped in for 60 days 😕
Be that as it may you got a 30 day visa exempt stamp (NOT a visa on arrival)
and
you can extend that ONE time for 30 days at the immigration office for 1900baht