The number's a fake! A fake!

Is there such a thing as a reverse phone lookup that is completely free? Mom's car was parked on the street at my apartment last week, and someone bumped the car (doing about $500-$1000 damage) and being a good citizen (or so we thought) left a note with a phone number. Well, Mom called the phone number, and got a woman who had no idea what she was talking about. Mom thought it may have been another medical student who lives in my apartment building, because the note was written on the reverse of an "Information About Your Medications" piece of paper, which would seem to come from a student or nurse or doctor, etc. So she went upstairs and asked his fiancee, who said that the writing wasn't his.

I tried searching that phone number, and I got results, but every reverse search is going to make me pay $14.95 to see the results. Boo! I remember when they were free.

So Mom has lost all faith in humanity. But if someone was going to leave a fake number, why would they bother with a note in the first place? If anybody has any suggestions, I'd love to hear them.