Rodale Books Sent unsolicited book and has turned over to Collections Pennsylvania Internet

I was on Rodale's website for "Heal Your Whole Body" book on 3/14/2015.  I started the order process entering my name and shipping address.  Then I clicked on to next page where it requested my credit card information.  My husband walked in and I told him thatI was going to order the book and he pointed out that I already had a similar book.  So I backed out of order process never confirming the order or entering my credit card number.  The book turned up at my doorstep a couple weeks later.  I sent their bill back with the above information informing them that I would be more than happy to return their book that they sent mistakenly.  I would need their information to return it to them on their dime.  No response.  I replied to their e-mail bill with same information and no response.  Bills came for about 6 monthes and nothing until a bill from a collections group appeared today.  They will never get their $50.  Everyone should know that if this hits your credit report then you shoulld file a dispute and put an explanation on it.  Also everyone should contact their Attorney General office and file a complaint.