This is Nathan.
Could I speak to Angela, please? I was just calling to (ask) ... Angela is on the phone.
Please leave a message. Call me later, OK?
Call me back (at the office / on my cell).
Hold on. I have another call.
I can't hear you. You're breaking up. It's hard to get ahold of you.
Oh,l'm sorry. I think I have the wrong number.
We got cut off.
Can I call you back?