Hey, JImmy!
To keep a track of every unfollower you should use Followeraudit.
Followeraudit is a great tool it will provide you with real-time alerts whenever someone will unfollow you and who unfollowed you.
It is not just an unfollowers tracking tool! It has many other amazing features too, like -
1) identify fake and inactive followers
2) get followers growth stats
3) unfollowers stats
4) detailed unfollowers stats.