When the police announced that they caught the person who helped them escape from Singapore, the objective was to warn potential smugglers against harboring them and helping them to venture further, beyond Malaysia. They became popular overnight, and nobody came forward to offer them inroads to Thailand.
At first I thought it was the mySejahtera app that they signed in and out at malls that caught them. But since it was the Royal Thai Police who provided information on the whereabouts, then it's clear that the credit card transactions of the Thai chiobu that landed them in the hands of the police.