As soon as you feel uncomfortable. You should try the resolution center first, which just sends them a message through PayPal says that they need to provide thier information, that way an attempt to communicate is on record and you don't waste PayPals time, it will last twenty days before it closes. Then after they haven't responded or are still dodgy you can escalate to a claim if the seller still hasn't provided the item or tracking to prove that the item is in transit (you can do this before the twenty day mark if you see fit). Paypal will almost definitely side with you if you haven't recieved the item and tracking is not provided.
Last edited: Mar 16, 2018