Then how about I apply for a new winner

Hello Number8998.

Steamgifts didn't see that you own this game because it's deleted from the Steam store. If a game's information is not available in Steams API then there's no way to check for it.
There's other things though: The sites rules require you to only enter giveaway that you don't own - so you'd had to check. While I understand that hardly anyone does that and simply relies to the site's settings (which has it's limitations as we've just established) there are tools that make this a really easy task. ESGST as an extension or Steam Web Integration as a script.
The first doesn't let you enter titles you own and the second shows you a green checkmark besides every Steam Store link for titles you already own. That way one can directly see if something is already owned or not. I can only recommend using SWI.