Dear May,
First, thank you for your kindness to this dog when his owners left him for several days with inadequate food.
I would suggest reporting this situation to the Selangor SPCA's animal welfare team. You can file a report here:
http://www.spca.org.my/contact-us/re...l-in-distress/
They can send one of their folks out to investigate and to talk with the dog's owners. If they feel the situation warrants it, they can escalate the case to the Selangor DVS, which has the authority to seize the dog if necessary and to file a criminal complaint.