Game glitch in library

I bought Call of Duty Modern Warfare 2 a couple weeks after it came out on my pc off of Battlenet/Blizzard. I recently got a new pc and redownloaded battlenet and when I look for the Modern Warfare 2 version it is nonexistent. I try to look at the shop to see if it says I dont have it purchased but when I click to “buy it” it says its in my library which it is not. I go to Account Setting off the app and it also states I have purchased the game. How do I find it?