Well how did you introduced the coral to the tank? Did you acclimated it? Looks like it has hope... You need to tell your LFS
owner that LPS
are ZOOPLANKTON feeders not Phyto... With a LFS
that doesn't know the basics, then his animals aren't going to be very good cared for specimens... Well, you have come to the right place!
You have to try and feed it at night while the feeder tentacles are out. Hopefully they'll come out maybe 2 or 3 hours after you turn your lights out. I know it will be tough, but at the beginning you have to do it... Try a pice of raw, peeled shrimp no bigger than 1/4 inch in size. Also your nitrate reading should be a bit more specific try getting a good test kit, Salifert, Sera, LaMotte... Optimally it should be less than 5ppm.
and Good Luck!!!