Boring visa question (Bangkok)

Hi all,

I have a boring visa question, but after several trips to the immigration office Im done trying to get information from the people there :P

So the situation is that Im doing an internship till the 5th of Febraury. my current visa will expire the 12th of December, so I need to get a new one. Question is....how do you get a new Tourist visa if you are already in Thailand. Feels like a stupid question, but my current one I got at the embassy in The Netherlands not sure how to go about it here.

Im not getting a work visa so that leaves two options really. Going abroad two times and getting a 30day visa twice....but thats a bit of a pain and expensive as well. The other option would be the 60 day visa, but not sure how to get that one. Are there any othe roptions Im missing?

Thanks in advance! :)))