votrechien - 1:37 am on Mar 22, 2011 (gmt 0)
The best thing you can do is post a fair rebuttal to the review.
It's easy to become very defensive, especially if you feel the review wasn't fair, but try to take responsibility as much as possible. Chances are you probably could have done things better in some area, no matter how small. Express that. It shows you as a moral merchant, and morality trumps mistakes every time.
On a side note, if you're offering a refund for the customer to remove the review, you likely messed up in a fairly significant way. A small gesture such as a future credit is sometimes necessary to ease an unruly customer, not a full refund. If a customer deserves a full refund, you shouldn't need a bad review to motivate you to do this.