They fixed the part themselves due to time constraints as we were late delivering and they couldn't afford to waste time to send back to us for repair. They deducted money from their invoice due.
The reason to capture ANY instance of customer dissatisfaction is to understand if and when systemic issues exist that need to be prevented from recurring; in essence, a corrective action. Business benefits from learning from mistakes, but only if they embrace customer feedback, good and bad, and react accordingly. Organizations that are not interested in learning are too dysfunctional to prosper.