@Ca**
CHECK your paperwork and see if it's addressed to Vientiane or Savannakhet. IF it's addressed to the thai consulate in Vientiane you can't use it in Savannakhet.
Get someone who can read thai to look at it if you can't tell. If it's addressed to Vientiane you're going to have to have your company re-issue paperwork addressed to Savannakhet..