I'll call you back
I’ll call you back means I’m ignoring you and I’m very good at it.
You’re still on the phone. I’ll call you back. (You’re now the phone.)
You’ve been talking about your boring job for 10 minutes. I’ll call you back. (You’re now the boring job.)
Your sister called to tell me about her new toaster. I’ll call you back. (You’re now the toaster.)
xs