Any mods help with this AZ claim?

Order 113-3244514-3094652, Buyer filed claim with seller faulted. However, I do not believe this should be true. It was premium 2 day shipping. Customer purchased 2 day shipping on Monday, Dec 23, shipping bought with Amazon buy shipping UPS 2 Day Air Monday Dec 23 and scanned into UPS same day and delivered Dec 26 on time. I think they are counting Christmas Day as a day when it shouldn't.

Appealed, but did not get denial email, just the same canned original email stating we debited the amount from seller.....So, not sure what that was about and not getting a denial email.

Plus, the UPS tracking shows proof of delivered handed to "name of customer" same as on the shipping label.

I purchased the correct 2 day shipping for the 2 day delivery per guidelines, so it shouldn't be late and tracking shows delivered on time besides Christmas Day.

Can anyone look into this for me? The customer clearly received order and proof from tracking shows this. I should not be held accountable and take the ODR hit.