Amazon.com/billwaus review: Unauthorized charges

Every month i am charged $8.55 for amzn.Com/billwaus.It has different transactions number beside the last one is366fe6jd3. What is this. There has been fee as small as $1.06 to $90.94. Please what is this? since i don't know what it is i would like for it to stop being taken out of my account. Thanks.