Creating a basic process for refunds that staff can follow consistently

Two employees handled almost identical refund requests differently last week. One apologized and offered a replacement; another immediately refunded, and neither did anything unreasonable. But customers should get predictable treatment, and staff shouldn't have to improvise under pressure. I'm drafting a one-page policy with examples, an approval limit and a clear exception route. What would you put in it so it guides judgment without becoming a rigid script?