How Do You Deal with Unreasonable Refund Requests?

It's incredibly frustrating. You work hard to create a product that genuinely helps people, only to have customers come back and ask for refunds after they’ve fully benefited from it. My team and I established a clear non-refundable policy from the outset to prevent this exact situation. Yet, here we are, dealing with requests that completely disregard the terms they agreed to. When I get these requests, my initial reaction is to ignore them. But I worry that some might file a credit dispute, which could lead to even bigger losses. How do you handle situations like this?