At All In London we don't want business owners to feel helpless about negative reviews but at the same time we don't want to delete genuine comments from customers. In our experience the best way to ensure that the business's reputation is maintained is to openly respond to negative reviews, this can turn the situation around in your favour and show other users that you're not unreasonable and are dealing with it professionally.
Here is an example of a business that has replied to a user comment: response example
. In this example the business manager shows a professional and rational approach that would only serve to give new customers more confidence in the business.