Missing dlcs

nicotah​  If you can't register the codes, and the content isn't already attached to your account, and it's not attached to a different account that you have access to, then there's nothing to be done.  From everything I've read, EA customer support has no way to manually add the content to your account, and support won't issue a refund for a purchase from more than maybe a couple months prior.

I bought the dlcs a while ago when they were on sale. I don't remember if I ever downloaded them. I still have the receipts but the serials don't seem to work on the download site.  I never had EA accounts merged.

nicotah​  Did you only recently buy the worlds?  If so, please see the first post of this master thread for how to register them or what to do if you can't:

[Current Issue] Sims 3 Store world can't register/install | EA Forums - 11143823

If you've owned the worlds for a while and they disappeared, that's a different matter.  In that case, let me know whether they worked previously as well as whether you've ever had EA accounts merged.