Can Monit be configured to never unmonitor/timeout a service?
I would simply use a cron job that would run monit start servicename at the desired intervals. Of course, you can use groups for a finer control.
I had the exact same issue where despite restarting monit, it would refuse to monitor after the timeout. Finally figured out had to delete the monit state file (/var/.monit.state) and restart monit to make it monitor all programs again.