One of the issues with Evri is that the package isn't really confirmed as lost and until they've paid you, this can take about 2 weeks after you've made the claim. I've had several packages go "missing" with them, I've issued a refund to the buyer, only for it to turn up at the their door a week later.
But as others have said, if it is low value, just refund it. Some people are just too cheap.