In other sites like Humble Bundle, you have a "Customer Service" tool where you can do the refund of the purchase or get the direct link of the customer.

Just like https://itch.io/dashboard/purchases but with the possibility to copy-and-paste the link of the customer, do the refund directly if it's requested (and possible), etc. These options could improve the user support a lot and avoid re-directing them to itch.io support. In the best case, creators should be able to complete the whole user support experience without re-directing them to itch.io.