In reply to Alex.

You're all right, and wrong. The gotcha with the EU 'cooling off' law is that it does not apply to online digital content if you have started downloading the content so no digital sellers do not have to refund in all cases.

If you have purchased and downloaded the content (e.g. Plugin), then installed and evaluated it does not suit your needs and the seller has a record of the download attempt against your Order then the seller is not by law required to refund your purchase. Messy huh?

(I think refunding on incompatibility reasons is just good practice)