The expiry date of my visa has crept up on me, and I need to run to grab the 30-day extension from the Bangkok Immigration Office today. Problem - don't know where it is. I hear its far to the north of the city - the Sathorn one closed a few months back, no? I'm fine with taking a taxi there, but can anyone tell me where I need to go?

Also: I have an non-Immigrant B visa from my previous job, but am now working as an intern and don't have a work permit. I want to switch to doing the tourist visa thing. Will an extension be granted without issue, do you think?

There is no 30 day extension on a non immigrant visa entry. The most you can obtain is 7 days and may require an air ticket out.

Immigration is at end of Soi7 (6 lanes) on Chiang Wattana Road. It is in south-east corner on first floor (entry ramp floor).