When all else fails, send an email that will make them think it's a real meeting.
Subject: Urgent: Phantom Call Follow-up
Dear [Name],
I wanted to follow up on our last discussion, and I'm still waiting to hear back from you.
However, I've been experiencing some... unforeseen circumstances that have prevented me from reaching out to you in person.
Would it be possible to schedule a real meeting at your convenience?
Best regards, [Your Name]
Advanced Schedule Manipulation Techniques