That is in the bit opposite Khun Woodys shop, next door to CAT office.. A buddy used to have a daily lesson with them, he isnt fluent but he is more than basic conversational.
When I first moved here I went and got thier workbook for about 200 baht and did the lessons with Wifey... It was actually a good leg up then, the basics, the kind of they go, he goes, she goes

etc.. Of course you HAVE to have a Thai speaker to do the pronunciation with.
They run classrooms, small groups (2 - 5 or 6 I guess) and 1 on 1 at different fees.
I am with Dodge, in that I think if your here long term you have to get some basics, food orders, time, directions, where is, what is etc.. But I am ambivalent about the time investment required for fluency (and I would say a LOT more than 2 years for fluent unless fully immersed and speaking all day) I am never gonna go and live upcountry, my life and lifestyle doesnt need it, and I am unsure about my investment in Thailand as it stands. To spend hours of my life to learn a skill that is not essential now and maybe dont need in a few years at all is a tough call. Dodger is different, he has a new family, he is putting down roots. I am a gypsy kid whose moved around all my life, never lived any place longer than 5 years as an adult, and have itchy feet. Who knows where I am in 5 years time.