What is too abstract in a contact list ? If the payment comes with a tag like refund the UI could display as such and if it comes with e.g. VAT then that.
How is this any different? The tag in this case is the address and the payment is being delivered by the block chain (direct submission for user->merchant is easier than merchant->user) so we can't stuff extra data anywhere else. Then the UI knows it was a refund payment and not for anything else.