I'll call you back later this afternoon
Could you please call back when you have a moment?
She said she would call back after checking her schedule
He promised to call back with more information
I tried to call back, but the line was busy
Hi, this is the automated system for Dr. Ramirez's office. How can I help you today?
I need to reschedule my appointment for next Tuesday, please.
Okay, I can help with that! Can I get your phone number, so I can call back and confirm the new time slot with you?
I will call you back later when I have more information
I will return your call later when I have more information
I will phone you again later when I have more information
I will get in touch with you again later when I have more information
I will contact you later when I have more information