dead space 2 activation wizard problem

Hello, so I recently bought a HARD COPY of Dead Space 2, about 6 days ago. I installed it and everything seemed to work properly, until I stumbled upon a very frustrating issue: the activation code that came with the game did not work, I entered it like 20 times and the activation wizard simply displayed a window saying: "The serial you entered is invalid, please contact costumer support for blah blah blah". Because I hate relying on costumer support, I decided to reinstall the game from scratch. And it did not solve the problem whatsoever, the same window kept coming up and I couldnt do anything about it. So just today I returned to the store and had it replaced with a new copy, and I installed it again and entered the new serial and, as you may imagine, the same window popped up again. I really like this game and it would be a real shame if i had to get a refund simply because this new "system" for online activation that EA has developed is beyond obsolete and completely useless.

I have tried two different copies of the game and none of them work, so please would you be kind enough to tell me how to fix this problem? I am running out of patience. I tried entering the serial in this manner 0000-0000-0000-0000-0000 and like this 00000000000000000000 and none of them worked.