The catch-22 is that these people are nearly always immigrants, and the criminals have taken their documentation, so the best case scenario is they get rescued and then deported, possibly via a spell in immigration detention. The worst case scenario is the cops turn up, laugh, collect the day's bribe money and then the person who called the cops gets beaten.

(this is an important dynamic in sex trafficking as well)

The government is somewhat complicit - there are even reports that the police take escapees back to their captives for a bribe

From TFA:

>The relative leniency of Muzahir’s compound, says Harvard’s Sims, likely stems from scam operations’ sense of total control in Laos’ Golden Triangle region—a zone of the country controlled largely by Chinese business interests that has become a host to crimes ranging from narcotics and organ sales to illegal wildlife trafficking. Even human trafficking victims who escape from a compound there, Sims points out, can be tracked down relatively easily thanks to Chinese organized crime’s influence over local law enforcement. “These guys don’t have to be held in a cell,” Sims says. “The whole place is a closed circuit.”

What you see is exactly how those systems function