Roly polies TOTALLY eat plants! In fact, I think it was my bean plants that they liked a couple years ago, too...
I had some luck relocating them by putting out a damp, rolled-up newspaper near my plants overnight. In the morning, roly polies were hiding in it & I just trashed the whole thing. I did that another time with either canteloupe or a grapefruit; I can't remember which. Just cut it in half (and eat some of the yummy fruit so the bugs don't get ALL of it!), prop it upside-down overnight and toss it in the morning.
You could also try setting out a shallow dish of beer overnight to entice roly polies and others...they'll crawl in & then drown when they can't get out. Roly polies do like decaying matter, so maybe provide a good layer of compost for them to munch on?
Good luck! Pests are the main reason my thumb is so brown.....