Ordered August no delivery

I ordered a necklace from BidorBuy by the seller Melinda Hefer. Auction ***<br> Won 30 Aug 15 21:02. It is now Dec I still haven't received my parcel .I contacted Centurion post office this morning they confirmed that I received 3 parcels and there are no other international parcels addressed to me. Melinda do not answer my mails and the online talk devision of BidorBuy can't help me. I spoke to a guy called Isaac twice. I wanted to changed Melinda's rating but BidorBuy refused to do it for me