The Thai sugar companies are run by big, powerful mafia families, and you don't take them head on.
I remember back in the late 90's Kasit Thai Sugar executives assassinated Australian investigator Michael Wansley, when he uncovered financial malpractice.
Sugar mill owner Pradit Siriviriyakul allegedly bribed Police $4m and said "it was good the foreigner is dead", yet he was acquitted by three judges.
https://www.smh.com.au/world/thailand-reverses-death-sentences-for-two-men-who-murdered-australian-michael-wansley-20150225-13oy7r.html