Poor service delivery and attitude

Book order delivered on Friday minus one of the books ordered; when email sent received the answer\ our system does not have this book on your order you must have deleted it please check your invoice and our website' the book is on the invoice and website and the credit card slip as proof of purchase. Since I have forwarded this proof to them there has been no response. The telephone number for this business has a machine that answers and then periodically tells you which caller number you are