Rapid technological advancement has fundamentally transformed consumer purchasing behavior, leading to the widespread adoption of online shopping channels. In this context, timely product delivery has become a critical determinant of customer satisfaction and loyalty in dual-channel markets. At the same time, growing environmental concerns have increased the importance of integrating Corporate Social Responsibility into supply chain decision-making. Motivated by these developments, this study develops a dual-channel supply chain model that simultaneously incorporates customer loyalty, delivery-time sensitivity, and Corporate Social Responsibility. The novelty of the study lies in its integrated analysis of these three factors within two distinct payment schemes, namely real-time payment and prepaid systems, under both decentralized and centralized decision-making structures. Optimal decisions are derived analytically and numerically to determine the pricing and operational strategies that maximize system profits in each setting. Furthermore, sensitivity analysis is conducted to examine how customer loyalty, delivery-time sensitivity, and Corporate Social Responsibility elasticity affect the decision variables and profitability of the supply chain. The results show that increases in customer loyalty and Corporate Social Responsibility elasticity enhance overall system profit. In addition, Corporate Social Responsibility elasticity influences most decision variables, except the wholesale price, manufacturer demand, and retailer demand. These findings provide new insights into the role of payment mechanisms and sustainability-oriented strategies in improving the performance of dual-channel supply chains.