Probably just a bad signal. Call back later. If you are getting a message in Thai you are calling the prefix correctly. Probably just out of reach of the station.
they have been on ASEAN now which used to be Thai Visa forum for a while but guess they thought is better to have their own prescence. I guess it is just branding- you see the name you may use the familiar. I actually appreciated their advice there because at least you knew they were hands on dealing with it every day.