Well I spent over an hour talking to a EA tech on their chat. After doing god knows how many things and trying to unlock it on the bioware site. Nothing. They were no help at all, and so all I can suggest to anyone with this problem is get your money back. The tech told me I could take the game back and just buy it on origin, I said not a chance as it's 5 times the price.

Yeah Right!! Bought & Downloaded Dragon Age: Origins Ultimate Edition on Origin,Now the DLC isn't Autherized. Come ON EA !! Sort Yourselves out.

Yeah I was told to g back to GAME UK about it.... but the thing is EA print the Serial codes? Right. So surely it should be on them if they PRINT THE WRONG CODES! Which is clearly the case...

Was having the same issue. Spoke to someone called "Shelby" using online chat. She was fantastic. Understood my issue and managed to attach the games to my Origin account and emailed me the keys too. Honestly never had such a good customer service experience.

The first advisor I contacted, sent me to the retailer for the new code, which is silly, since EA is responcible for printing codes on the manual. I contacted another advisor, named Nischal, who was far more helpfull and solved my problem.

I had the same issue and after seeing this forum, I gave live surport another shot after the first person told me to go back to the retailer. The second time the person I had was brilliant and now on my way to downloading it :D 

I have repeatedly tried to get the EA Staff with whom I am in contact to pass the word to the the EA Game Advisors about this problem.

The printer's mistake on the physical stock provide to the UK-based retailer GAME is well known.  The Staff here on the AHQ tell me they keep prodding the Customer (dis-)Service wing of EA to address this properly.  It keeps not happening.

The only possible solution is for the players to keep trying through the Help Center until you reach a Game Advisor who got the word and will issue you a new product code. 

That's it.  There's no other solution.

See this thread for the "official" response:

I had the same problem. I live in Germany and bought DAO + Awakening through Origin's own store but unfortunately, the game was only available in German through the client just because of where I live! THAT support person couldn't change it to English. That was 2  weeks ago. I decided to buy the UK Ultimate Edition version through Amazon, so I can play in English and when installing tonight, I too, only had 16 digits. 

Support was great about it and I am downloading the Ultimate version through their client right now. It's probably going to take all night at this rate so I will go to bed lol. Go chat with someone knowledgeable and you'll get help. 🙂