You do not need to talk to anyone, just proceed this way.
Has a reasonable time passed your item's last estimated date for delivery, and you have not received the item?
Then, if the seller is not being helpful, go right of the item purchased, and from More Actions select.... I Have Not Received My Item.
If you are not fully refunded within 3 days, you must escalate the case on day 4 or within 30 days from opening the case, and eBay will step in and force the refund.
Do not close the case early for any excuse or promise the seller may give, and do not forget to escalate.
Only a valid tracking number showing delivery to the name and address you have registered with eBay for your ' Delivery Address', will close the case in the seller's favour.
@norgated
