It's more likely you were disconnected than a purposeful hangup. But if you phone back, you'll probably get a different agent.
They have extra hours this weekend due to the approaching extended filing deadline. They should be open tonight until 9 PM Pacific (12 Midnight Eastern). And tomorrow 5AM-9PM Pacific (8AM-12 Midnight Eastern).
FAQ: What is the TurboTax phone number?
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
What do you mean by leaving out a whole Schedule C? Did you go through the interview questions for the self-employed business section?
Have you already filed your return? Or are you reviewing it prior to filing and can't find the Schedule C?
