I recently changed my billing info for monthly autopay of $.99 for I Cloud. Now I am being billed $12.99 for PUBG Corp Tencent Mobile International LTD. WHY?? I did not authorize this purchase. I am getting

Unless you have subscribed to whatever PUBG Corp through your Apple ID, and also have Paypal as a payment method on your Apple ID neither one would have anything to do with your iCloud subscription whatsoever.

If you are just seeing these notices as emails or even SMS messages, but are not relfected on your actual payment method's statement, then they are likely just scams. Coincidental to having changed your payment method for iCloud, but unrelated to it.

You can verify any and all active subscriptions on your Apple ID by following the steps here: See or cancel your subscriptions - Apple Support

You can verify the validity of the email invoices you got for PUBG by following the steps here: Identify legitimate emails from the App Store or iTunes Store - Apple Support

You can also contact Apple Support directly if you believe these invoices are somehow related to your Apple Account: https://www.apple.com/emea/support/itunes/contact.html

If you have Family Sharing set up check on any of your children have signed up for a subscription. If they did, it may not show up on your device.