DVD key is incorrect

I bought the boxed game from the Game store. Installed it and it wouldn't play.
It advised me to uninstall and then reinstall again, which I tried.
The problem is that it keeps telling me that the serial number key i have entered from the back of the manual is wrong. Just to satisfy my curiosity, I tried installing the game on my laptop and another PC, all with more than enough spec and everytime tells me that the serial number key is incorrect. I have asked other family members and friends to enter the code but it always comes up as a "wrong code" I can get no further than the enter serial number box.
I have also tried disabling the firewalls and virus programmes. It's all very baffling. Having read through some of the other threads it appears that the fault is common and is nothing to do with my pc's/laptop.
If anyone has any ideas that may help, then please speak up!|||Contact EA support..