There are several reasons why an order may be returned to sender. Here are some of the most common reasons, although the exact cause will depend on the specific circumstances of your order with joujou.ch:

Delivery Address Error: If the delivery address provided is incorrect or incomplete, or the recipient's name does not appear on the mailbox, the carrier may be unable to deliver the package, resulting in it being returned to sender.

Repeated Absence at Delivery Address: If the carrier has attempted to deliver the package several times without success and without being able to contact you, the package may be returned to sender.

Refusal of Delivery: If someone at the delivery address has refused to accept the package without a valid reason, it may be returned.

Damage in transit: In rare cases, if the package has been damaged to such an extent that it cannot be delivered, it may be returned to sender.

To understand the exact reason in your specific case, it's best to contact joujou.ch customer service directly. They will have access to the details of your order and will be able to explain precisely why the package was returned, as well as the steps you can take to resolve the problem.