This is a warning to all players who have purchased Guild Wars 2 or are considering doing so. Gaile Gray has taken to the Guild Wars 2 forums to explain some players who are receiving an Error code 122. I will allow Gaile to explain your situation:
If you receive an Error 122, that means that your code was disabled. Most likely this means that you received a fraudulent code from a third-party seller. If that is the case, you will need to contact the seller and get a refund so that you can purchase the game directly from buy.guildwars2.com or from a legitimate reseller.
The Error 122 is very specific and does point to a disabled code. If you purchased your code directly from us using a legitimate credit card, and you feel that you received the message in error, please submit a Support Ticket.
Thank you.
If you bought Guild Wars 2 but not from the following list of retailers, the key may not be valid and disabled by Arenanet. You will be responsible for contacting the retailer you purchased from and obtaining a refund. Be wary as numerous incidents of fraudulent boxed copies have also been reported, meaning resellers are buying boxed copies and then performing chargebacks, and the codes inside of the box are being disabled. Be on guard, even if the game is being sold at a brick and mortar store, if it is not on the list.