If you're new to Upwork, there's an excellent chance you're about to be scammed. Google Hangouts = scams. Please read before proceeding with this "client":
re: "To use upwork call protection, what number do I give client?"
You already know these Google Hangouts people are just scammers.
But just FYI:
There is no such thing as "Upwork call protection." You may be mis-remembering "Upwork payment protection," which is real, but which has nothing to do with phone numbers.
By the way... Upwork has no rules at all against sharing your Skype ID or phone number or other contact information with clients, whether that be clients you are actually working for, or even clients you are simply interviewing with.
If a prospective client asks for your phone number, you may give her your number. It could be your real number. It could be a utility number such as Google voice number that you set up purely to use with Upwork clients.
But doing so doesn't violate any Upwork rules.
Most of us DO make our own rules about what kinds of contact information we share with clients, and when we share that information. Use wisdom and stick to your own policy.
Most successful freelancers don't simply give out all their contact info to any client they interview with. But many of us are willing to share certain information with serious clients, especially after being hired.
re: "What do I do to unresponsive freelancer"
Stop working with her.
Continue working only with the people on your team who actually respond to you and do what you ask them to do.
If you need to hire new people, feel free to do so.