Unknown Purchase

I’m charged 3.99$ per week. But I don’t know why I’m charge it. And in my purchase history, there is no such a purchase in the list. But every week I’m receiving a alert from my bank that a detection of 3.99$ for APPLE.COM/BILL ITUNES.COM.

How to get to know why I’m charged it. How to stop it. How to make arrangements for refund it