Yes, Robinhood offers 24/7 phone support, but you need to request a callback through the app.
How to Request 24/7 Support from Robinhood:
Open the Robinhood app and log in.
Tap your Profile Icon (bottom right).
Select Help → Contact Support.
Choose Request a Call and describe your issue.
A Robinhood representative will call you back anytime, 24/7.
For assistance, you can also try calling +1-(888)959-3148. However, the callback request through the app is the best way to get direct support.