i_am_blokeman,
I agree with all of the previous posts, these fish should not be collected and sold to hobbyists until someone can come up with a food substitute for acropora polyps.
I question the integrity of any LFS that ever sells these and other obligate coral eating fish as they are almost always destined to starve.
You should take them back to the LFS if they allow returns.
These fish will more than likely die of starvation unless you have a large tank of acro "colonies" (50-100 pieces) that they can feed on. I only know of a select few people who have kept these alive in reef tanks and they had over a hundred colonies of acros for them to graze on.
If you do not have many acro colonies you will also lose the corals in a short period of time since they will decimate the polyps quicker than your corals can grow. The only reason the people I noted above have been able to keep this fish along with healthy acros is because they have so many corals the fish are allowed to "pick" on several different pieces thus allowing the corals polyp production to keep up with the fishes feeding.
I had a friend sustain a pair of this fish for about 2 months by mushing mysis shrimp onto a dead coral head. The fish ate the shrimp off of the coral head but still slowly wasted away over the course of a few months.
Acropora are hard enough then to introduce a predator! Yikes!