What does "it’s in a parcel shop" mean? It sounds as though you nominated a click and collect address for delivery? If so, it's up to you to collect it. You can't claim a refund if it's been delivered to the store you selected.
Do this quickly - the shop only has to keep it for 7 days. If not collected within the time limit it should hopefully be returned to the seller, but this can be uncertain and there's a real risk that you could lose you item and your money. You should have received a collection code from eBay, which the shop will require.
If you didn't make this as a click and collect purchase, could you explain more fully, please.
