Contact customer support, with the a photo of the original activation card and a copy of your id etc they should be able to help you. They may need any credit card associated with the account as well (Not sure if GW1 had a cash shop). Best to contact them and find out.
Just contact them, they may be able to ask you a few questions, if you answer they could help you out. Happened to me with Swtor, too bad the game sucked so bad.