While the specific error you mentioned has already been addressed as listed in your other question, in general if you find a problem with a Wizards of the Coast product you should contact their customer service department. While I know most people tend to dread the thought of contacting a company's customer service, Wizards has nice people who want to help you be a satisfied customer. They can help direct feedback to appropriate people within their organization, or get you replacements if you received a defective product.
At the bottom of pages on their web site is a "Customer Service" link, pointing to http://wizards.custhelp.com/, which has support articles you can search and also lists several methods by which you can contact them:
Send a message on their web site
You can send a message with your questions or concerns. This requires setting up a "Wizards account" on their site, which you may or may not already have.
You can push numbers into a handy Wand of Telecommunication and actually speak with a human being far away, much like the Message spell but over a much longer range. In North America the number to dial is 800-324-6496, available seven days a week from 9am to 5pm Pacific Time. (They happen to be Wizards of the West Coast.) Contact information for other regions of the world is also available on their support site.
The @Wizards_Help account is an officially monitored account where Wizards customer support reads and answers questions and comments.