The only thing you can do is open a case of " item not received" and explain the circumstances... however if tracking shows as delivered... the seller believes it has been and eBay take the stance that it is delivered and you probably would not receive a refund.
This seems unfair on both buyer and seller... but a seller should not have to refund for an item they have genuinely packaged and posted and which is shown as delivered, albeit on the doorstep as this is the couriers doing. All you can do as a buyer is to make it known that you did not receive your item and possibly have to prove that it was not " delivered in your hands"... Postal couriers , I believe, need to stop leaving parcels on doorsteps, particularly those in full view of roads etc, or by bins or under cars when they could be " stolen"... it is just not acceptable when paying for a service.
I do know that a buyer who challenged the " delivery process" of their purchase not being in their hands, won the case after appeal and eBay refunded the purchase price. I cannot say that this would happen in your case though.
@wikchyl_0
