My message is being cut off at the '&' character (ampersand)
If you're using our API, this is probably because you're not URL encoding the message body string.
You need to URL encode the message body. Here's an example on how to do it in PHP: http://www.php.net/manual/en/function.urlencode.php
e.g. ."....&message=" . urlencode($body)
If you're still stuck with this, ask your software developer to contact us.
If you're not a developer and are using some software to send SMS and this is happening, please contact the company who developed the software you're using.