Failed renders are refunded
If a render fails, the credits go back automatically, keeping their original expiry date.
Credits are taken before the render is attempted, and returned automatically if it fails. You do not need to ask.
The refund goes back into the batch it came from, so a refunded credit keeps its original expiry date rather than quietly becoming a shorter-lived one.
A panel that failed shows failed — redraw on the artboard. Redrawing it charges again, because that is a new attempt.
More on credits and plans
Did this not answer it? Open the ? menu in the studio and choose Get support — the page you were on travels with the message.