I’ve had the same issue. From reading on Apple.com, it indicates that charges could be made by a relay account (if you have Apple+). Another way is if you have another account that’s been setup (possibly a family member). Since the charges on card don’t list the name of the app (and it could be more than one app), one charge can include several charges. Unfortunately, I was in the hospital x3 for 5 weeks, and sick afterwards, so it was well beyond the refund policy of the card (which was 90 days in my case). I’m some cases, I was able to contact the venders (if I saw activity of a certain vender, and was able to get a few apps cancelled). In my case, I had no family members in my home that could have created an account. Sometimes, you might receive emails from the vender. If I relay account was used under the same account, it will show up, like “how are you enjoying our product” or “it’s time to update”. I currently use an Apple Gift card instead of credit card. I hope this helps.