And how scary the phrase "They denied a half plane full of people" sounds it still means that the other half did get the visa that fits their purpose and length of stay and entered Thailand without any problems.
Avoid extra costs by flying around the globe to jump hoops and play games, get the correct visa and you can stay inside Thailand without fear of being cought out.
Enough suggestions. I always like the advice based on I never heard, which is total nonsense as it might happens regular only you did not pay any attention to it.