How do I deactivate iMessage so I receive messages on my new phone?
In some cases, moving from an Apple device to a different type of device can cause problems receiving SMS messages. This is due to the Apple iMessage setup.
To deactivate on your phone: Tap Settings from the home screen. Tap Messages. Move the iMessage slider to OFF.
If you no longer have access to the phone, contact Apple Support and they can assist you in deactiving the device.