We had a customer went to credit card company to get her money back.
We had the car, we fully checked, found no faults. She left it with us for months. We also did a report for the credit card company
Finally got hold of her, and it turns out the card company had refunded her..... but, and I assume they got our report, they then took the refund back off her!
Cost us nothing! Just make sure you reply to credit card company queries when you get them.