I may be running 2 movies together in my head, but hopefully not. I remember watching a black and white movie on the sci-fi channel last year where a lady went to a department store for one specific item. I don't remember what the item was, but she got on an elevator and it took her to a floor with only one desk and one sales clerk. The clerk sold her the exact thing she was looking for, after leaving she was told that the floor she claimed she went to was either empty or didn't exist or some such. I believe in the end it turned out the 'sales clerk' she encountered was actually a mannequin that had somehow come to life. I know this is vague but if anyone remembers the name of this movie please post it, thank you.

Sounds like the Twilight Zone episode After Hours which was remade in 1986.
The After Hours - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/The_After_Hours)

Yes that is what I was thinking of! I was mistaken thinking it was a movie. Thank you!

You're welcome.