As said there is only the one on Soi 5, Jomtien. There are specific desks in there, but you use an arrivals one to have your paperwork checked and get a ticket to move on to the correct one. Look up what copies and form are required, and they want to know the reason for needing a residence certificate, plus an original TM30 slip. THe main Bangkok Bank Branch on second Rd (opposite soi 6) used to be best, but these days things are not so easy,