I lost my cd key, but got one from live chat, why doesn't it work on origin

hi, I got a new computer, dug up my old mass effect box and cds, but it seems I lost my game authorization code, I got on live chat and explained to the live chat assistant what happened, they approved my request for a new key, but when i plugged it in to Origin product redemption, it says the code is invalid, is there a reason this is happening? I have tried multiple variations of the code they provided me thinking maybe I wrote it down incorrectly, but no luck.

Thank you

Edit: it is for PC if that was not clear