Today there is no doubt about the relevance of complaint management for customer retention, which, among other things, results in improved repurchase behavior. However, what happens when organizations are not aware of which customers are satisfied and dissatisfied? What happens when complaint management cannot assess the repurchase behavior of their customers? Which consequences in terms of sales revenue must decision-makers then take into account? To address these questions, we present a decision support approach—based on findings from evidence controlling—to find out what influence repurchase behavior of customers has on the achievement of distribution goals. For this purpose, we develop a system dynamics model for complaint management to analyze the effects of repurchase behavior of satisfied and dissatisfied customers. The research findings suggest that the application of system dynamics supports identifying relevant feedback loops in complaint management and furthermore provides information to what extent repurchase behavior influences distribution goals.