Disagreeing slightly with the relaxed consensus. Two out of 190 is fine at $39. The reason to fix it now is that the same behaviour at a higher price and higher volume is not two people, it is a pattern that specific communities pass around, and the ones who do this find products by price point.
So yes, keep the friendly policy, but add the revocation clause and add a small amount of telemetry: flag any refund request from an account that completed its main action within an hour of purchase. Not to refuse them, just so you can see the shape of it when the volume is ten times higher.