The additional charge might be for a product or service you purchased recently. Check your Plans & Products page to view the products and services you have subscribed to.
It is possible that your payment for the previous month could not be processed because your credit card details changed or the payment was otherwise declined by the bank. You would have, therefore, received two charges: one for the previous month and one for the current month. Check with your bank to find out if there was any issue with the payment for the previous month.
If you have multiple Adobe IDs (email addresses), you might have purchased products separately on different Adobe IDs using the same card. Check the order history on your Plans & Products page for each Adobe ID.
You might accidentally have placed an order twice. For example, there might have been a typo in your email address when you first tried to order, and then you ordered again with your correct email address. In this case, an additional charge appears for the order placed with the incorrect email address.
Or, you might have paid for another person—for example your family member, employee, friend, or colleague. The charges appear in the bill you receive.
If you cancel your membership, a cancelation fee is charged as per the subscription terms. The cancelation fee reflects in your subsequent bill.