Clownfish are actually members of the Damsel family. It is not uncommon for damsels to host in an anemone. Your domino damsels are known as the "holy terrors of the reef" as they are perhaps one of the most aggressive fish on the market. They have been known to attack their keepers hand and draw blood defending their territory.
I personally know of one who killed two triggers twice it's size and one volitan lionfish!!!
IMO, unless you want a real aggressive tank, remove the damsel and take it back to the store!