I need to be able to talk to someone about charges to my account. What is the phone number please?

There is no one direct number.

You can use the general Apple Support number for your country of residence, and follow the audible prompts to get to iTunes. You can see the list of numbers here: Contact Apple for support and service - Apple Support

You can also log in to https://reportaproblem.apple.com to get a list of all charges made on your account within the last 90 days.

The more direct way to contact iTunes Billing is to fill in this form: iTunes Store - Contact Us - Apple Support

Beyond that, if you got an email stating you made a purchase, or your account was actually charged, make sure the email is actually from Apple. Identify legitimate emails from the App Store or iTunes Store - Apple Support