When i get a review, i always thank them no matter what compliment or criticism. But I am getting annoyed with start reviews with 0 stars but a nice written review. or they had one small complaint. I always try to answer them no matter what. but i try to word it in a way to make sure the rest of their service was good. make them think about the inbetween stars.
I always try to contact them right away if there was a issue. But sometimes clients will write their review weeks-months later where its a moot point, I can't fix the issue at that point. i always thank them and let them know for future refference if they have other concerns to let me know right away and I can correct it for free, or given a discount or refund