Yeah, I mean, I understand them being charged for the failed trade-in. Their credit card was charged, so Apple supposedly got the money (from Goldman Sachs). Why did they still block his account (owned by Apple) when he failed to pay his credit card bill (owed to Goldman Sachs)?

The department that handles these problems is unreachable by phone instead of very interested in edge cases and false positives. That's an intentional choice.

The weakest link in Apple’s chain is the return and tradein fulfillment side. They use distinctive boxes for trades and the clown car of couriers — FedEx. Many of the couriers doing pickups at FedEx are private contractors or subcontractors, and their loss rates are high between pilferage and incompetence.

I’ve personally experienced two occasions where iPhones have been stolen in transit by FedEx personnel — one vanished and one, bound for an Apple repair facility in Pennsylvania, was delivered to a residential address a few miles from my city.

In neither case was Apple aware, which was surprising to me as they typically have their shit together. I only realized there was an issue on the one occasion where they were going to charge me for a replacement device, and checking the tracking indicated the phone was delivered to a stay at home mom. The whole process must be outsourced to a meh contractor, and insurance cleans up the mess.