COD Black Ops install issue

My Black ops was grey to play now so I uninstalled the game and when I went back to try to install it again it says buy now? What’s going on why can’t I install it

Hey there!

After taking a look at your account’s purchase history I can see that your purchase was declined. Before re-attempting your purchase, be sure to try these solutions to common payment issues.

If you need more specific information as to why the purchase was declined, you will need to contact the bank associated with your payment method or submit a support ticket for our Game Master staff to review.