SIMS 3 invalid registration code.

I purchased a digital copy of the sims 3 from gamefly.com. They have since moved to direct2drive.com which is the absolute worst website ever, won't allow gamefly customers to reopen their accounts, will not respond to concerns sent to their customer support via e-mail, their twitter account. I still have the serial code through gamefly but the sims 3 website tells me the code is invalid. Can we not register codes that were from digital copies? It is very frustrating that I can't use a game I purchased because of the poor service of some other company!  Any help greatly appreciated.