A to Z claim do I need to respond

As you all are probably experiencing more packaging lost during the Holiday season.
We are doing FBM and we have just received A to Z claim in relation to order lost which was granted to the customer and no need to provide other documents. Im ok with this decision and wondering if I need to do anything? If there is no action to be taken on Amazon how can I contact customer to explain why this has happened?
And can I to do anything to improve my account health?
Thank you for your help.