Why does not My Sims 3 serial code work?!?

I just bought The Sims 3 Collector's Edition. Today, I put on the disc, spent for all instructions, and then I type in the serial code located on the back of the package inside the box. Type I in a couple of times and says invalid code. I also try to sign up at thesims3.com and says my code is invalid. I'm sure I've written on the right, but …. idk, what do I do??? = (No, not second hand. I just bought it, brand new, yesterday,

It is pre-owned?

Teaching Kids To Code