Re: I have Sims 3 Pets, but it does not show up in the game
@paulbarbee Where did you buy the pack? If it came from an unauthorized seller (for example, Ebay or g2a), it's possible that the codes were originally stolen or otherwise fraudulently obtained. Over the past year, EA has been systematically deactivating codes for which it was never paid, even in accounts that owned the corresponding packs for years. So it's likely that your Pets code falls into this category.
The only way to get the EP back on your account is to buy it again. If you're interested, Steam is having a sale right now. You'd have to buy the base game again, but it would still be less than the full price. Plus, you'd get1,000 more SimPoints for registering the second base game (or another copy of WA, for that matter).