Iphone replacement at Genius Bar

My ear speaker wasnt working so i brought my iphone into the Genius Bar. They told me they would replace the glass and told me to return in an hour.

Upon returning, they said they decided to replace the phone instead. They presented the new phone and I was on my way.

Now that Im home, Im a little worried that my old phone never got restored to factory settings and that all my info is on the phone. Has anyone else experienced something similar? Should I be worried?