<![CDATA[The rise of social media has amplified consumer voices, enabling collective phenomena such as cancel culture and digital boycotts to rapidly affect brand reputation. This study examines how negative sentiment and boycott campaigns on X (Twitter), Threads, and Instagram, triggered by public complaints regarding account-blocking practices at Bank Mandiri, influence brand trust and customer defection intentions. The study focuses on the August 2026 case involving the freezing of personal and donation funds belonging to a civil-society activist coordinator from Pati, Central Java, shortly before a planned demonstration in Jakarta. The incident generated the hashtags #BoikotBankMandiri and #PindahDariMandiri and attracted attention from the House of Representatives (DPR) and the National Police Commission (Kompolnas). Using a qualitative descriptive approach combining a literature-based case study and netnographic observation, this research analyzes online firestorm patterns, customer narratives, and the bank’s crisis response. The findings indicate that slow or perceived non-transparent complaint handling can transform individual grievances into collective boycott calls, weakening brand trust through perceived unfairness, limited communication transparency, and negative electronic word-of-mouth. However, declining trust does not necessarily lead to account closure because switching costs, habitual usage, digital ecosystem integration, and corrective responses may moderate customer defection intentions.]]>
