Well, as should be obvious, I'm still no expert on Bangaiis. They seem to be hit or miss at acclimation into a tank. Once acclimated they seem to be very hardy. I got the guts to try a bangaii again about a month ago. Instead of ordering it online, I got it at the LFS, so the stress from transport was significantly reduced. It is still doing very well. It even made it through my recenty catastrophe where I lost my 4-line wrasse, lawnmower blenny, flame angel, and 2 scarlet cleaner shrimp. Given the animals that died, I am suprised I did'nt lose the bangaii as well, which confirms the theory that they are hardy once acclimated into a system.
Sorry for your loss of fish, hope it was covered under a guarantee. And welcome to saltwaterfish. Looks like you have probably been lurking for a while but didn't post till now.