Guys, guys, it is a news to be condoled; not an opportunity to spread "what I would do if I am in charge".
To be fair, first although Thai police would not be the top-of-the-line when you figure, the point is "the take down" occures at Thailand, but the "hijack" took place at who-knows-where, and at "Golden Triangle", the border on a map didn't actually exists. If China like many sugguests, pushed the one country who "unfortunately" have the boats ported too hard, next time the people down the ground (ie. Thai border patrols) would choose a simple solution that shoot off any suspetious boats comes around, let other freaking country's government to take the blame from the mighty dragon. - So victims actually dies even faster next time, if any.
Second, "Incompetent foreign government" is one thing, "do the jobs FOR the incompetent foreign government" is another thing. It is a COLD fact for the families of the victims, it is a cold FACT for the reality world. China do not "rules" the centre-south peninsula (I don't use the know-nothing-racist term of "Indochina peninsula", because it is a racist term in fact - but to point it out this time), send in boys or send in H-6s loaded with neutron bombs would not improve the "social security" of the non-governmental "Golden Triangle" area, but only stir unified hatrate to "the bully Chinese" - people would happy to slughter Chinese by-passers for sports next time.
Third, specific to this case (other than the abovementioned overall geo-political situation), what China can do, is to cooperate and formally push the Thai government, (in a sense) root out corrupted police in regards this case (like plawolf pointed out evidences), strengthen the law-enforcement measure in the area one way or another (push, and send in advisers, inspectors alike), and formally cooperate "You have difficulties for PROPER HOSTAGE RESCUE MISSION, I will comes around and take over the mission (and took the responsiblility) next time, with your blessing".
Put in this way, Germany spells as a successful country overall, but in 1972 Olympic Games it did not actually that "success" in terms of doing a good police work in time of crisis - did the rest of world, especially the victim state took the measure to beat the German state, hammering the "loser state" so that we would have a better tomorrow? It appears didn't ends up that way. Yup Thailand is not Germany, and China is not Israel, but the rational is the same.
I would not be supprised if PLA or PAP special forces has been send in the area for some "proper response to a genocide" one day, but it will be with the blessing and fully cooperate of the host state(s), and such response would be "not more, not less" kind of enough, rather than "took over the job".