Gosh! That's confusing
If someone on Facebook left your friend request unanswered, then you unsend the friend request then send it again, will they get a notification that you sent them a friend request again?
Yes, they will get another notification. However, be aware that after so many "tries" (of you sending and the other person not confirming), FaceBook will no longer send that request through.
You really shouldn't be "friends" unless you can contact them outside of Facebook, anyway.
So just contact them, and ask if they overlooked the request.