You can get your W2 form from Pizza Hut in two ways:
1) Use the online web portal dedicated to Pizza Hut employees. Pizza Hut's parent company Yum Brands runs this service, and it can be found at https://teampizzahut.yum.com/
You will need a username and password, both of which should be issued to you by a manager, or the HR department directly.
2) If Pizza Hut are making it difficult for you to get hold of your W2 form, then look up the Pizza Hut HR director for your region on social media (they're usually pretty easy to find on LinkedIn) and keep bugging them until they promise to look into the matter for you.