If an eSIM does not work and you have not used the data, we refund it in full to the original payment method. There is no restocking fee and you do not need to return anything.
In practice we check the line on the carrier side first, because most failures are a stuck data session that we can restart remotely in a few minutes. If the line genuinely cannot be made to work in your location, we refund.
To be straightforward about the limit: once a plan has been used, a refund is no longer possible, because the data has already been bought from the network operator on your behalf. In that case we look at a replacement instead. If a plan was never activated, the refund is simple.