Robokiller app won't delete from my iPhone

I deleted the RoboKiller app, but it’s still in there, even though it shows that the app is not there. It continues to put all of my calls into SPAM. I reload the app and it will not let me sign in. So I need to find out how to delete it without being in the app. I’ve I deleted the RoboKiller app, but it’s still in there, even though it shows that the app is not there. It continues to put all of my calls into SPAM. I reload the app and it will not let me sign in. So I need to find out how to delete it without being in the app.

[Re-Titled by Moderator]