Five delinquents must find a way to survive when they are sent to a behavioural camp run by a sadistic cult.

Dig it!

Consider the following to strengthen your logline:
1. Anything more to these delinquents? They may just be a motley crew of felonious youths with nothing in common except being forced to this camp – and survive. Any elaborations may help to provide an ironic play on words for your premise.
2. What’s this sadistic cult’s MO – what are they known for? I read once a boot camp that had “fight nights”.
3. A camp destination/location is key for reader orientation.
4. Most camps have a set timeframe, maybe you can use this as your ticking clock devise e.g., “… must survive a three day …” just food for thought.

This is what I can see so far:
“A group of delinquents must survive a behavioral boot camp ran by a sadistic cult”

Hope you found this constructive, keep going!