I am surprised you cannot find anything - okay I have limited experience but it seems that everywhere I go they are looking for English teachers. Try Satun and Trang - I could hardly set foot in these places without being offered work.
In Bangkok get a list of all the schools in Silom district - send your cv. If you want a quick fix go to The Nature Method Language Institute by Kao San, or look regularly in the Bangkok post for opportunities.
Warning though - although the Nature Method can get you into work very quickly they promised me they would sort me out with my work permit etc - but these where empty promises - never mind - I soon found other work and left them. Don't worry about having signed a 12 month contract - it is not worth the paper it is written on.