Now on tt the problem:
It sounds like a swim bladder infection. You can try a broadspectrum antibiotic (like e-mycin) in a quarantine tank. You may actually try Maracyn and Maracyn 2, they are different broadspectrum antibiotics that treat different infections. It has been my experience, though that if a fish can not right itself in the water, it's too late. I have never seen one make it through. If you have only had the fish for 2 days, I would certainly be contacting my LFS
to express my displeasure.