Simcity (2013) - Can't redeem a preowned copy bought from CEX?

So, I bought a disc copy of Simcity 2013 in CEX today. I pop in the disc, and it tries to get me to install Origin. Impossible as far as I know, as EA has moved away from the platform. 

I thought I'd try redeeming the long code via the EA App. I pop it in, and at first it comes up with "Code Accepted", my username and such. But then when I click confirm, it goes back to the code entry screen with a message saying "code already redeemed". Game does not pop up in my Games Library. Unless I'm doing something wrong, I'm assuming it's the fact it's a disc copy that's been used before...? And if so, is there any way I can go about getting this assigned to my account? Would be nice to play a game I have bought, especially one that is ten years old now, regardless of source. 

Thanks in advance!