Game unavailable

I have purchased I am cat and played it lots in the past. The game has now disappeared from my Library.

It’s listed in my purchase history but when I click on it to redownload it it is asking me to pay. 

my headset was replaced a few weeks ago due to a fault but I can play all the other games I have previously purchased

Please could you advise as I don’t want to have to buy the game again.

Thanks