When you call them, you'll probably get the company line of "On hold means that your application is on hold and will be reviewed soon. Once it has been reviewed, we will notify you of your status. Your status right now is that it is on hold."
The good news is that you haven't been rejected straight-out.
The bad news is that, this late in the game, you're probably in the "slow reject" pile. For example, I'm still "on hold" at a couple of places from LAST YEARS' cycle.