Serial code in sims 3

Why won't my sims 3 serial code work!? I'm so irritated and frustrated! I've tried it so many times in so many different ways. Whenever I type in the code, it always says it is invalid (when I try to register my game at the sims 3 website that is). I don't understand anything. I bought my game at a store, and not at the internet. Is it someone I could contact or something? Or could someone please help me? If not I could rather just use a unused serial code or something. Please help me someone!
Asked Mar 22, 2013

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