If you have a REAL tourist visa <- that you bought at a thai consulate before you arrived here and were stamped in to thailand for 60 days you go to the main immigration office at the government complex (Building B) out on Chaengwattana Road. Here;
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You want counter J in the immigration office
However if you didn't buy a visa before you came here and were stamped in free for 30 days you're not here on a tourist visa, (and in fact it's not a visa at all) just a free entry stamp and to get a 30 day extension on that you go to the immigration office at IT Square Laksi Plaza here
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