Prevent users from joining a meeting via mobile phone.

A new national regulation applying to some of our meetings with external participants prohibits access via mobile phone. We have already found a solution that involves muting the phone's audio. Could you please suggest a solution other than leaving people in the waiting room? We need a solution that automates the process when the meeting is created—one that detects phone-based access and blocks the user. Thank you, and have a nice day.Clara