On Harry Potter and the prisoner of askaban how do you beat fairies?

In Harry Potter and the Prisoner of Azkaban, you don't really "beat" the fairies. They aren't enemies to be defeated, but rather creatures that are easily distracted and mischievous. Here's how the characters dealt with the fairies in the movie:

* Distraction: Hermione Granger used a bit of her own brand of charm and wit. She distracted the fairies by offering them sweets.

* Patience: The fairies are easily bored. Harry and Ron learned that if they simply waited, the fairies would move on to their next target, leaving them alone.

So, the key to dealing with fairies in the wizarding world is to avoid engaging them directly and instead use distraction, patience, and perhaps a little charm.