Urgent quiz help needed re completion status and not allowing multiple attempts

I'm stuck and this is a bit urgent. I've been using Storyline for a couple months, so I thought I'd better reach out to the experts in the community.

We just migrated to Absorb LMS from eLogic. We have several timed quizzes with both graded questions and essay/survey questions. Only one quiz attempt is allowed; if the learner loses internet connectivity or quits in the middle for whatever reason, they should not be able to access and re-launch the assessment again.

My questions are:

• How can we prevent the user from being able to log in and launch the quiz more than one time?
• How should completion/tracking status be handled? I've tested adding a completion trigger, but if the person quits mid-way thru the quiz, the status shows as "In Progress" so they are able to go back into the LMS and re-launch the quiz. 
• Is there a way to tell why a user stopped the quiz without finishing it? We can manually re-enroll them if they had a legit internet connection disruption, but we want the quiz completed in one sitting.