Just got confirmation from a "Service Provider" and South African passport holders CAN indeed apply for visas at the thai consulate in Vientiane but NOT Savannakhet..
So go to the eVisa online website, select the Non-B for the reason you're applying see what documentation is required, have your employer compile it, GO to Vientiane and apply online for the eVisa
This is how that system works up in Lao now, you have to physically be IN Lao, you upload your Lao visa/entry stamp as proof, you apply online with the eVisa system then take the confirmation to the consulate and pay in CASH for the visa.. It should be approved within a couple working days after that
*******************************************************************************************
*****
3