If getting a 2nd opinion proves the card is faulty, and OC have declined to offer a full refund or exchange (which you are entitled to decide on which you want, not the supplier, plus you can reject a repair), you are also entitled to what is known as consequential losses. That is any costs associated with the card.
Testing fees, postage costs, cost of any additional hardware you purchased with the card that would be for use with the card etc.
Thanks, will try.