This chapter introduces two empirical studies to analyse the adequacy of complaint channels. In detail, five communication channels (mail, e-mail, phone, face-to-face and social networks) as complaint channels are examined from a customer perspective with regard to five dimensions: procedural justice, interactional justice, distributive justice, personal attitudes and social interaction. First, to test the adequacy of the complaint channels, a one-way analysis of variance is conducted for each dimension identified. Differences among the adequacy of complaint channels towards customer perceptions are revealed. Second, a cluster analysis provides detailed insights into customers' preferences regarding complaint channel choice.