I'm sorry. I think I have the wrong number.
Could I speak to...?
Oh, hold on. I have another call.
We got cut off.
Call me back on my cell.
You're breaking up.
Hi _____! This is_____.
When the phone suddenly ends.
When you want someone to return your call.
When you can't hear some of the other person's words.
When you need to interrupt because you have another call.
When you ask to speak to someone.
When you call someone by mistake.
When you leave a voice-mail message.