This is a user issue not an ebay issue.
Let me explain the seller (a user) is not abreast of the new rules, or has no clue how to use the site.
Either way tell them you have paid and they can see that detail on the the payment part of the order itself.
If they are unsure they can contact eBay CS who will confirm this detail and to send ASAP.
Hope that helps
Live long and prosper