Can you clarify if you tried loading any of them to a brand new card number yet?

If you got a brand new, never been used, card and tried to load the money pak to it, and it still fails and directs you to the refund site, then, yes, I'd say GD definitely needs to fix 'something' for you. But, from what I can tell, you haven't given this an attempt yet, or am I mistaken?

If you don't want to go that route, why not make the refund request in someone elses name, and to a different address? Granted now that you've already attempted to get a refund, and they know the cards 'were once' (i.e. 'probably still are') yours it may not work. Try on a single one and see.

Or of course you can take some legal action and perhaps prevail, but, that will take a lot more time and effort.