I had one returned for the very same reason just last week.
I had posted 2 items on the same day - one to Tennessee and the other to Macau.
The AP staff had stuck a customs label on the rear of the parcel, but they put it on the wrong parcel. So the item addressed to Tennessee had the customs paperwork for the item going to Macau... meaning the parcel had 2 different barcodes aligned with 2 different addresses.
I opened the item in front of the AP staff and identified it as the US order. They repacked the item and shipped it via international courier at their expense.
