@Terri *********
Before you do anything, I suggest you Facebook search "visa service Kanchanaburi". A Thai guy called Day. He speaks English. He is NOT an agent. He does border runs from Hua Hin. He will tell you if you can cross the border with a South African passport. Circumstances change. You never know. He would definitely confirm if you can or cannot. If he can help you he will arrange to pick you up in Hua Hin. Worth a try