Is it possible to delete a customer review that contains wrong information?
As of January 2015, you can in Itunes Connect:


Sign in to Itunes Connect
Go to "Contact Us"
Choose "App Store Questions"
Choose "Customer Reviews"
Choose "Specific Removal Request"
Click on the 2nd "contact us" link. A form should appear.
Fill in the form and push "Submit"
Wait for Apple to contact you.