Lost disc, sims 3 on Mac

[pixieamore23]

I bought Sims 3 from CEX last year for my mac and have loved every minute of playing, i have since moved house and seem to have put the disc away too safely.
i have found the box with the code but no disc. I have tried registering on the sims3 site, as i was told i can download the game from there with the serial code. I have an account but to do this its asking for my serial code, which when i enter it tells me it is not valid (i think the person who had this before has already registered it).
Other than buying it again what can i do?

[kindofagirl]

I would contact ea, I bought one of the expansions and my cd drive couldn't read the disk so I tried downloading it and it couldn't recognise the serial number, so I emailed, or it might have been live chat and they sorted it for me.