Thanks for your notifying us about the extra book(s) you received! Oops!
We would greatly appreciate it if you would submit a request with the SKU(s) number(s) of one or more of the extra books you received, so that we may locate the error. A SKU is a sticker on the spine or back cover of the book, it will look like this: A1-BCD-234.
We really appreciate your time and help with this.