Customer order stuck processing for 3 days

I had a customer whose payment was processing for 3 full days. I was entirely unaware of this order’s existence because it did not show up until this morning since it was stuck processing this entire time.

Not only has this item been marked as “0” on my inventory count for over 24 hours, Amazon has marked this order on my selling page as “Overdue”. This is the first possible day I can ship it. I ship my orders every single weekday. I just shipped all my orders yesterday.

So the shipment is both late AND I will have to be cancelling it, both things of which are the fault of Amazon taking 3 days to process a payment.

Is this something I can contact them about? This is completely unfair.