IDIOMS

phone tag

(idiomatic) A situation in which two individuals attempting to contact each other by telephone repeatedly do not get a live person and instead trade messages, such as by voice mail.

Example: 2000, Sharon MacDonald, Gilbert Cockton, People and Computers XIV - Usability Or Else!: Proceedings of HCI 2000:
  "What frequently results is a game of phone tag. One party tries to reach another, is unable to, and leaves voice-mail indicating an interest in finding a time to meet. The other party returns the call, more often than not fails to reach the original caller, and leaves voice-mail in response."
2005, Dorothy A. Maxwell, Phone Skills for the Information Age:
  "Avoid phone tag, which results when two parties go back and forth trying to reach each other by phone."
2006, Steven Fishman, Working for Yourself: Law & Taxes for Independent Contractors, Freelancers & Consultants:
  "To reduce the time you spend playing phone tag, ask what time the client will be in and call back then."