cd keys?

I know when I called them up to get a refund for that disaster known as Diablo 3 they used my Starcraft 2 cd key to verify my identity.  If you still have your cd keys for your accounts that sure seems like a way for you to verify your identity to them.  Maybe call them up and ask if there's some way to use your cd keys to verify your identity.  Offer to mail them in.  I would think possession of your cd keys would be a pretty good indicator of ownership.