Unauthorized payments

Do you mean you're getting a recurring charge and not sure what it is?

check here

See or cancel your subscriptions - Apple Support

or other billing related stuff..

Subscriptions and Billing - Official Apple Support

Apple will never charge you without your permission.

If you were charged by Apple for something there are a few possibilities:

• You purchased it from the app store (or subscribed to a service) and forgot you did
• Someone you share your phone with purchased it from the app store
• Someone you share your Apple ID with purchased it from the app store
• If you have a family sharing plan, someone in your family purchased it from the app store
• Your Apple ID was hacked and the hacker made a purchase from the app store - for this one see ➡️  If you think your Apple ID has been compromised - Apple Support
• You were not actually charged for anything; the message you got was a scam to steal your identity - see ➡️  Avoid phishing emails, fake ‘virus‘ alerts, phony support calls, and other scams

The bottom line is that Apple never charges you for any purchase without authorization. So someone with access to your account must have made the purchase or subscription, if it wasn’t a scam message.

If it is a specific item on your bank or credit card statement see this link ➡️  If you see "apple.com/bill" or an unfamiliar charge on your statement - Apple Support

You can review all of your purchases as described in this link ➡️  See your purchase history for the App Store or iTunes Store - Apple Support

If it is a subscription you can cancel it here ➡️  See or cancel your subscriptions - Apple Support.

Note that subscriptions are not canceled when you delete an app; the subscription must be canceled separately from deleting the app.

And you can request a refund here ➡️  Request a refund for apps or content that you bought from Apple - Apple Support

2 payments have been taken for Roblox without my permission

2 sums of money have been taken out of my account for Roblox without my knowledge

See my post right above yours.