Write a non-confrontational response to the customer's review with some specific keywords that let them know you've read and understand their review. Express sincere regret that the customer had a poor experience.
Thank the customer for taking the time to give you honest feedback.
After you've apologized to the customer, make an offer to discuss the situation further and make things right.
Avoid stating your business name in the review so that it is less likely to be found in a search engine query.