In Thailand, you have to really watch what you say and who you say it to.
Thailand people are hell-bent to sue for defamation, slander, and more importantly, poor reviews.
Even if the company deserves a negative review, doing so you may find yourself getting sued.
It is very important when you get upset, not to lose your head and say something you may regret later. Best to hold it in than get sued.
Sometime it is just better to say nothing at all.