They keep calling my work number.

This is a Craigslist scam.  Texted "My step dad would like to know if you still have this for sale so make sure you email him at malcompatrick01@gmail.com if you are still having it. Thanks James." A quick search of the email address showed the same exact text sent to others from a different number.

And what you do next is to send this information (search engine results) and the link to this webpage to abuse@gmail.com