Follow the steps in this article:
If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement - Apple Support
If you still can't find out what made the charges,
Contact apple by the link in that article.
or:
Contact Apple for support and service - Apple Support
To stop a subscription follow the steps in this guide:
How to cancel a subscription from Apple - Apple Support
When the subscription shows Expires on [Date]
That means the subscription is canceled.
If you are still unable to cancel the subscription:
Contact Apple for support and service - Apple Support
You can request a refund by following the steps in this guide:
Request a refund for apps or content that you bought from Apple - Apple Support
You are not guaranteed a refund tough.
This is an automated process, if you wish to explain your situation in-depth to a person you can:
Contact Apple for support and service - Apple Support
Also, see this:
How long refunds from the App Store or other Apple services take - Apple Support
Good luck!