A-to-Z Claim for Non Delivery

I fulfill my own orders. One was lost in the mail and never arrived. Customer never contacted me and I received a notification that Amazon had approved an AtoZ claim against me this morning. It never arrived so don’t mind returning money and going after post office for insurance but why didn’t I get a chance to refund without an AtoZ defect? In previous instances where they went straight to an AtoZ without contacting me the AtoZ was approved but without a defect given to my account. Can I get Amazon to remove the defect?

TLDR Can I appeal an AtoZ on the grounds that I was never contacted by the buyer? (Not to get money back but remove defect)