Apple Watch Activation lock

Only the original owner deactivate the activation lock on the watch.

Contact eBay and ask for a refund unless the list specifically said it was activation locked. The watch may be lost or stolen.

Apple will not help

In case you need a second opinion, what lllaas said is absolutely correct. You cannot bypass activation lock without the assistance of the owner who put the lock on. Apple won't help. You have a useless wrist ornament. Return it for refund.

I agree with lllaass