They aren't codes as in "secret codes" designed to hide a message. They are 5 or 6 digit number you can send text messages to. In response, you receive various kinds of information ranging from weather to political info. There is nothing hidden or secret about it. It is just a shortcut rather than a hidden message.
Not too familiar with the issue at hand but do know that premium texting is racking up some bills for people. Also, the person getting them blames the carrier for the bill dispute.