I've been charge for something I don't know

if you just got some mail saying you were charged

then read

Identify legitimate emails from the App Store or iTunes Store - Apple Support

and

Phishing & Other Suspicious Emails

and https://en.wikipedia.org/wiki/Phishing

if you were charged because of a subscription read

See or cancel your subscriptions - Apple Support

otherwise you can read

Request a refund for apps or content that you bought from Apple - Apple Support

I was charged over $200 for something I didn’t approve it on an app called episode and I want my refund