Hey lc04do65la2e,
Is your FC Mobile account linked to an EA account? You'll need to be signed in to the same EA account linked to the FC Mobile account to successfully redeem the code.
In this case, seeing as the code was redeemed but the rewards aren't in your account, they may be in a different EA account. You'll want to contact live support so they can take a look at your account, as we can't support account-related requests here on the forums.
Please note that if you bought the code from a third-party retailer, it's best to contact the retailer directly for a new code, as EA live support might not be able to help. Thanks!