Dragon Age 2 DLC

I purchased a physical disc copy of DAII: Signature Edition, with the idea that the DLC would come with the disc and I would not have to purchase separately. However, the DLC comes in a form of 25 character activation codes. The game keeps telling me that the codes has already been used even though I bought the game new. I would guess this also may have to do with the BioWare website being merged into EA.

Does anyone know how I could get the DLC installed without having to buy it again?

Thank you in advance.