Happy to help and hope this works out. How wonderful to raise service pups
I'm sure you were very disappointed to read about toxicity.
Maybe a light barrier of burlap on stakes, if you see berries. Out of sight, out of mind? Birds are supposed to like the berries and could get them from the other side.
Or as the shrubs grow, shear off the flowering ends each year.
Last idea, post locally for free giveaway to someone who will remove them. It sounds like the ones who planted would consider putting them right back in pots and reselling.