Item refunded unrequested and not agreed upon.

[td270]

Few weeks ago I bought an item inclusive shipping cost from US to Europe and customs clearance fees.Few days ago I suddenly noticed the sale was refunded to my PayPal account without any request or agreement from my side to due so.Turns out this is due to some transport problems. According to the tracking log from Global Shipping the item would have been oversied.The seller claims this decision was taken by eBay only and beyond his control and he cannot do anything about it.Furthermore the procedure eBay proposes to have them involved doesn't work from this end it appears.Does anybody know how to tackle this one?.