It has cost me over 20 pounds for postage now and this is just way too far. To the other poster: Not a full system, its prebuilt.
given that they have supplied you a faulty card (3 times), should OCUK not be covering the cost of return postage?
When did you purchase the card?
does DSR and/or Sale of Goods Act not state that if an item is faulty, then the consumer can ask for a refund, repair or replacement at no extra cost to them? surely return postage is an extra cost.