they dont have an exact address on UK files for your international address ? then that is maybe the problem ? I have trouble even with UK addresses not going to UK addresses just because I missed off the word 'flat' or the 'house name' etc. Computers run Royal Mail now, if it was hand checked, maybe a human would have looked up the international address themselves, and then manualy over rided the computer rejection. Maybe, who knows.
But here is the thing...where is the package NOW ? If it goes back to seller in one piece and in good order, then surely a refund would be applicable? If the package has been stolen or lost and never gets back to the seller...then what? and happy smoking to the thieves lol :)