Sometimes it isn't easy to walk away from a decent-paying part-time job, even if what you're after is a full-time job. If I needed a job, I'd accept any job, even if it wasn't quite what I was looking for. I'm sorry to say that I wouldn't hesitate to walk away from a part-time job if a full-time job opened up. I don't think I'm a bad person for doing that. We have to do what we have to do to support our families. This guy resigned from the position within 24 hours. It's not like he left you in the lurch by being a no-show or something. I really think that you need to let this one go and focus your efforts on getting someone new to fill the position. I can almost guarantee you that you'll get more hits if you turn it into a full-time position.