"sorry, I cannot answer"
"Hello, this is Xion. I'm sorry I can't answer the phone right now, but leave a message and I'll be sure to try and get back to you as soon as I can. Bye."
"Hello, this is Xion. I'm sorry I can't answer the phone right now, but leave a message and I'll be sure to try and get back to you as soon as I can. Bye."