Sorry TB, not feeling too good today so my super sleuthing search radar is not functioning at it's best but this snippet from the DOJ site popped up:

Check the terms and conditions or contact the seller for expected delivery time. The seller is responsible for sending the items within a reasonable time.

Contact the seller immediately if your goods have not arrived within the stated time

Upon delivery, the buyer is not deemed to have accepted the goods until they have had a reasonable opportunity to examine them. Contact the seller immediately if your goods are damaged on arrival.

And this bit too which seems to indicate that it is the ebay and Paypal process which should be applied

Buying and selling on eBay and similar sites

You should first try resolving any disputes via their online resolution process.

Disputes over items not received, or received but significantly different as described can usually be resolved by direct communication between buyers and sellers. To facilitate a resolution, most of these sites provide an online process where buyers and sellers can communicate with each other.