Dissatisfied Customer Complaint / Dispute

We refinished a kitchen formica countertop for a customer in a color that we don't offer any longer. We tried for 6 days to please the customer but she now says we ruined her countertops even though they are usable, just not the color she wants. After the last meeting with her, we explained that we would try mixing colors and show her samples before we try refinishng the counter again or she could just pick another color. She doesn't want another color. After 4 weeks of trying, we received a fax of a Contractors invoice to have new granite and travertine installed. We did not make the customer pay anything but now feels that we owe her new countertops of higher quality. Should we have to pay for new countertops since no money has changed hands for the work done? Next step?