Apple.com charged me 51.35 an I’m unsure why

Have you checked your subscriptions?

Purchases - View, change, or cancel your subscriptions

Purchases - Subscriptions not billed through Apple 

Apple ID - If you see ‘itunes.com/bill‘ or an unfamiliar charge on your bank, credit card, or debit statement

If necessary, contact iTunes Support. Either use the form or scroll to the bottom of the page in the 2nd link. Follow through the screens to get a chat or telephone option.  

iTunes Support

iTunes Support – world wide

Hello!

Check out the links below in order to see what your were charged for a how to request a refund.

Request a refund for apps or content that you bought from Apple: https://support.apple.com/en-us/HT204084

See your purchase history for the App Store or iTunes Store: https://support.apple.com/en-us/HT204088

Let me know if this helps!

Try contacting iTunes Support using the links I posted above.