@xBlueSkyNL If you've already registered the packs, then no, the codes won't work. They can only be redeemed once, although as you've seen, you can still often use them to install the disc copies through Origin.
Are you totally sure they're not on your account already? Open your Origin game library, click on the Sims 3 icon, select More > Expansion Packs, and see whether you're asked to Buy Now on the packs you own. If not, then Origin knows you own them.
Otherwise, you can try entering any email address you can think of into the Origin login window and clicking "Forgot your password?" Any address tied to an Origin account should receive a password recovery email. Be sure to check the spam folder as well.
EA customer support is on limited hours right now: phone calls are entirely unavailable, and live chat is only open from 9 am to midnight GMT, Monday through Saturday. Sometimes people can't get through even then because support is swamped. But you can also try selecting a slightly different category of problem to see whether you get a contact option, for example missing content rather than code not working.
https://help.ea.com/en/contact-us/
When you do contact support, it would help to have a photo for each pack showing the disc, the box it came in, and the insert with the product key showing. You can upload the photos directly to a live chat session.
