To remove a member from the chat, go to the chat in the Supertext app, go to Settings Add members.
Verify that you have an internet connection and check so that you havn't accidentally disabled push notifications. Make sure that the app is uninstalled from your phone.
Download the app and follow the on-screen instructions to get started.
Downloading and using Supertext is completely free.
You can always reach your friends, whenever you want, when you want, however you want.