<p>In the current competitive landscape, where the sustainability of resources has become a priority, companies are coerced to create inventory systems that not only enhance profitability but also address environmental and customer-related issues. The importance of customer satisfaction and brand integrity, alongside the necessity of reducing waste and reclaiming value from returned items, has heightened the significance of reverse logistics in contemporary supply chains. This research formulates a unified reverse logistics inventory model for items that deteriorate in an inflationary context, where customer returns are remanufactured and re-entered into the market. The model features a dual-level trade credit system, where the manufacturer offers credit to the retailer, and the retailer provides credit to consumers. By optimally coordinating decisions regarding both new and remanufactured goods, the model addresses the complex financial and operational interactions among supply chain stakeholders. The suggested model reduces the overall cost of the integrated supply chain by simultaneously optimizing order quantities, remanufacturing rates, and dual credit durations. Numerical experiments demonstrate the model’s effectiveness, revealing considerable cost reductions and enhanced coordination efficiency relative to uncoordinated strategies. Sensitivity analysis emphasizes the considerable impact of inflation, deterioration rates, and return proportions on optimal choices, validating the model’s robustness and real-world applicability.</p>