Just ignore it. You should be able to set preferences to not receive reminders, I never get them and if I did would delete, I decide when and who I leave feedback for.
You don't say why ebay had to refund, the seller should have done this, if you have to escalate to involve ebay then seller has not done their job properly and feedback should say this, even if you just left a neutral saying "Unsatisfactory transaction" .
