How do I handle customer questions about discounts?

As an e-commerce business owner, I'm struggling with managing customer inquiries about discounts. Customers frequently ask about ongoing promotions, eligibility, stacking discounts, and understanding complex discount rules. I need a systematic approach to handle these questions professionally, maintain customer satisfaction, and prevent potential confusion or frustration that could lead to abandoned carts or negative reviews. How can I create a robust strategy for addressing discount-related customer questions efficiently and effectively?