Selling alone: what do you do the moment a customer asks for a refund?

We're building Arioo for people who sell something themselves: a course, a coaching session, a box that ships.

Checkout gets all the attention. I suspect the refund is where one person running a business spends their worst ten minutes, because there's nobody to hand it to.

So if you sell alone: what's the first thing you do when a refund request lands? Refund straight away, ask why, offer something else?