I know you are right. I'm not positive that happened to my steering wheel. DHL classified it as stolen by the USPS. I did go to the USPS sort facility, twice, by talking my way past a security intercom.
I couldn't get back to the package mangling equipment. I talked to a manager, they looked in the room where they keep "opened" packages, they had a special area just for automotive goods, nothing was found they said. They supposedly look through all the equipment and conveyors nightly.
For the USPS there are but 2 outcomes for a package in their care (I'm quoting them here) "you either get it or you don't". They have no have no mechanism to recover a missing packages, nor they care what happened to contents.