Try speaking to somoene differant in the service centre perhaps. I had this problem (Silver arrived no problem, Gold took three attempts) and two particular staff members in Bratislava and Warsaw were superb. The rep in the WAW office even offered to personally deliver it to me, and in the period when I had no card they sent lounge letters to various addresses (I was travelling IIRC) to ensure I got at least one of them.
Am fairly certain it was the WAW postal system at fault as other mail went missing around the same time, but was a classic customer service story of turning a bad situation and unhappy customer into a very positive outcome and satisified customer.
Don't forget to ask for your baggage tags to be-reordered. They come seperately, about a week or two after the card in my expeierience.