Hey Manny,
Sorry to hear that your peppermint attacked your corals
I have peppermints in my tank and they never have attacked any of my corals. Do a great job ridding my tank of Aiptasia though
I always read that peppermints were reef safe, are you sure you did not get a camel shrimp instead? They look very similar to the peppermints but tend to be alot more aggressive and destructive and are, unfortunately, often sold by LFS's as peppermint shrimp.