Republic Act No. 10173 (Data Privacy Act of 2012)
Section 4 — Scope; Section 11 — General Data Privacy Principles — Government Agencies as Personal Information Controllers
“This Act applies to the processing of all types of personal information and to any natural and juridical person involved in personal information processing including those personal information controllers and processors who, although not found or established in the Philippines, use equipment that are located in the Philippines, or those who maintain an office, branch or agency in the Philippines subject to the immediately preceding paragraph.”
The barangay as a government unit and the barangay captain as a public official are subject to RA 10173 when processing residents' personal information. Disclosing your case records to a neighbour without lawful basis is an act of unlawful processing. File a complaint with the NPC and the Office of the Ombudsman.
Civil Code of the Philippines
Article 26 — Dignity, Privacy and Peace — Civil Liability for Violations of Privacy and Dignity
“Every person shall respect the dignity, personality, privacy and peace of mind of his neighbors and other persons. The following and similar acts, though they may not constitute a criminal offense, shall produce a cause of action for damages, prevention, and other relief: (1) prying into the privacy of another's residence; (2) meddling with or disturbing the private life or family relations of another; (3) intriguing to cause another to be alienated from his friends; (4) vexing or humiliating another on account of his religious beliefs, lowly station in life, place of birth, physical defect, or other personal condition.”
In addition to the RA 10173 complaint, Civil Code Article 26 creates a cause of action for civil damages where a person's privacy has been violated. If the disclosure harmed your relationships or reputation, you may pursue a civil claim for damages as well.