Hello, I work in Xinhua Bookstore. Although the book you mentioned is not in my charge, as long as there are quality problems, you can return it by keeping the purchase invoice.

Don't go to the cashier. If you find a salesman in charge of this kind of books, you should be able to return them. If there is a quality problem, you can not return it. You can call Xinhua Bookstore directly, or complain directly to the person in charge. You should be able to get a satisfactory answer after reading it.