Brick.ie The Irish Association for Adult Fans of LEGO®

I have bought from Brickowl occasionally and never had an issue. However this time a shipment from Serbia has been stopped by An Post because they have deemed the accompanying paperwork was not sufficient and have said the item will be returned. I am trying to get this resolved with the seller and have requested a refund - no success so far. There doesn't seem to be a way of asking for Brickowl's input, other than contacting a general enquiry email address. Has anyone dealt with an issue like this before and how did it get resolved?

Thanks.