If you are trying to reach someone over phone or mobile and they have not been responding then you can always write them a Follow up Email After no Response. Shared below is the format for formal email after no response on phone or mobile which you can easily personalize to create an email that rightly solves your purpose.
Follow up Email after no Response on Mobile with Sample & Template
Dear Mr. Henry Smith,
I am Olive Ben from Zenith Technologies. I have been trying to reach you from past couple of days in relation with the enquiry you had made about our products at the Tech Expo in New York on December 5th, 2022. Your number has been constantly unreachable. You can call me at 9898989898 or you can share your alternate number where I can get in touch with you.
Looking forward for your response.