This is a member to member forum, not 'Ebay'.
If the buyer has opened a case for item not received, you should have added the tracking to the case.
If the tracking now shows delivered, the case will eventually close in your favour.
Otherwise, the buyer can close the case from their end or you can contact Ebay Customer Services and ask them to close the case.
You will still have to wait for payment - Ebay's terms now state you will be paid 2 days after tracking shows delivery.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
