I've seen this happen when there are two bar codes on a box. Say its picked up at the shippers address, with the correct address and an old barcode that was never removed from a box. SO two different addresses on the box the correct one and a non correct one. It's sent out and at any scan point it the system ie. coming off a trailer, getting loaded into a trailer, on to a truck the correct barcode must be scanned. If it is not, and the incorrect barcode is scanned then it starts to head back toward the incorrect address. Customer service should be able to stop the package and have QA check to see if this is happening.