Amazon Digital Services is a part of Amazon. An unidentified amazon.com fee for $0.99 is typical for apps.
A persisting $2.99 fee is generally the Prime Members every month charge for the Kindle Spare time enrollment for one child.
A $9.99 Amazon digital services charge is usually for the Kindle Unlimited service.
A $99 Amazon digital services charge may be for Amazon Prime user. At the conclusion of the free trial period, Amazon Prime goes directly into annual subscription and is charged at $99 automated for another period.
An $8.75 Amazon Digital Services charge maybe for the Hulu program after the trial period is finished.
You might have tried Hulu through Amazon, as well as inadvertently enrolled in the membership remedy automobile-renewal.