DPD UK review: Return of defective goods

I returned a pair of hearing aids which I bought from an American company called Oricle on 9 August but they didn't work at all. I returned them using DPD but they were held up at the airport awaiting a charge of $25.02 taxes. They were not a sale or a gift but DPD insisted on payment and said another company dealt with taxes. They were returned to me and Oricle have a 30 day limit for a return of purchase which has expired. This tax was not pointed out to me when I sent the goods via the post office.