I think you've been very unlucky. The 9800pro is an astablished card and has a good reputation. Out of interest, what make was the card?
If not wanting to try another 9800pro, how about the X700pro which I see they sell?
As to money back, difficult point but as you've had two fail on the trot...you could try and ask for a refund (or a credit note) and see what they say.