I need help with possible refunds of charges that were placed on my iTunes account

Hi,

Over the last couple of months I have received charges to my iTunes account and I am not sure what to do. They are not huge amounts, but I have placed parental controls on my kids iPads and accounts (or so I thought), and yet I am still getting app charges. I have my regular charges of music subscriptions and iCloud storage, but these are different than the regular monthly charges.

Can you help me?