import query1

I purchased an item from Germany and paid VAT when it was imported. The item turned out to be faulty, so I returned it along with receipts including that VAT invoice (charged by FedEx plus their fee) to the retailer. The retailier has sent a replacement and now FedEx have charged me VAT again. The FedEx bill says "you were indicated as the payer for those charges by the shipper". As this is a replacement for a faulty item should I be being charged VAT again? I paid VAT for the original item but seem to be now expected to pay VAT again on the replacement. There were no import charges as such, just VAT and the FedEx fee. Thanks