No, not right. Chaenwattana issues 30-day tourism extensions for ONLY those who entered a pre-purchased Tourist Visa and are stamped for 60 days. All other tourists are going to IT Square Laksi Plaza temporary office, just next to Lak Si station of SRT Dark Red Line.
BUT, you entered on Visa On Arrival (VOA) and were stamped in for 30 days. Unfortunately, VOA entry is NOT eligible for 30 days tourism extension. If you apply for it, you may be able to get an "application denied, 7-days to leave kingdom" stamp.
If you still want this 7 days stamp, You will go here.
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And you can book online here
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