Too funny! When I bought my first zebra danios eons ago (as a newbie-they were my first fish), the LFS clerk said they were zebra tetras. I called them that for a long time until I found out they were danios. The clerk accidentally said tetras (I asked her and she was embarrassed because she does know her fish). Sounds like the same type of thing happened to you. Your fish are probably danios, especially if you looked them up and they look the same.