I do't know why the vtext is not working for you but as a replacement you might try the Find My iPhone app. You can use your computer to make your iPhone "beep" so that you can locate it. Plus it will allow you to get a GPS fix on your iPhone if needed.
Oh my! Text messages are an important part of your service, so let's get resolved asap! Have you located the device without @vtext.com? When you send a message using @vtext.com what happens? Do you receive an error message on the phone? Keep me posted.
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