A-Z Claim granted - Royal Mail have signature and date and time of delivery

Hi,

We sent a parcel out via Royal Mail signed for, Royal Mail have a signature as well as date and time, customer claimed non delivery via A-Z claim. It has obviously been granted and refunded, is it worth taking further and appealing and any advice on what I should say in my appeal? ANy help appreciated. Its not the first time but its happening more frequently so wonder how others deal with it?

Kind regards

Burash Ltd