The activation code for my Crysis 2 game comes up with an error " serial number invalid, contact customer support".

I have just purchased this game and have a receipt, and I would like to now play this game.....!!!

I have tried the serial number in both formats:
XXXX-XXXX-XXXX-XXXX-XXXX
XXXXXXXXXXXXXXXXXXXX

When I log into my Origin account my serial number appears in the information area, but it still wants me to go through the Activation process, and then the error message comes up.

Please help

frustated