How do I handle complaints about products, services, or customer service issues in Korea?

For complaints in Korea there is a clear escalation path. Start directly with the seller or company's customer service, calmly and in writing if possible, through their KakaoTalk channel, email, or 1:1 inquiry, since many issues get resolved there and Korean companies generally want to avoid public complaints. If that fails, the Korea Consumer Agency handles consumer disputes and mediation, and you can file through their site, which carries weight because companies take its mediation seriously. For consumer counseling there is also the 1372 hotline. For specific sectors there are dedicated bodies: the Financial Supervisory Service for banking and insurance, and the relevant agencies for telecom. Culturally, staying polite but firm and persistent works better than aggression, and referencing the relevant agency often speeds resolution. Keep all records: receipts, chat logs, photos, and the seller's statements. The same consumer protections apply to foreigners as to Koreans, so do not hesitate to use them.