The link to this Pizza Hut on the website no longer seems to work:
http://www.pizzahut.co.uk/restaurants/find-a-hut/london/stratford/
I'm not sure whether it has been removed from the website by mistake or it has actually closed. (It is still listed on the Westfield website, it has a live FSA rating and uber eats still lists it as open - so I'm inclined to think it is is open.)