Why is my orchid dying?

[huntermaclean]

Maybe I simply got a bad stem from the lady at the flower shop, but I wanted to check with some experienced users first.

I bought this 5 stem orchid from a flower shop in Sheung Wan, Hong Kong. One stem didn't have any blooms on it, so they planted a fresh one for me, and it looked great. Several days later, the left-most stem (the one they planted fresh) started to wilt. Now, seven days later, that stem is completely gone and a couple other blooms have begun wilting.


We have only watered the plant once, 7 days after we received it; which is what the florist instructed.
It sits on our dining room table and is about 20 feet away from the only window which supplies light to it; we haven't moved it since we brought it home.

I went to the lady that sold me it and she wasn't much help beside trying to offer to change out the stem(s) for a price; kind of difficult when you don't speak their language. Is there anything I can do besides buying new stem(s) and having them re-planted?

Thank you for taking the time, I am very new to orchids and know nothing about them.