I would return it if possible.
From everything I have seen and read, Sebae anemones are one of the hardest to keep and more often than not die in captivity.
These are another animal that should be reserved for the highly experienced and very, very well established tanks that highlights anemones.
Too bad because they are some of the most beautiful critters anemones available, but alas, not suited to captivity.
I wish I could offer advice on how to keep them, but unfortunately with how young your set-up is and all, I fear it's chances are not that great, but not through any particular fault of yours.