Like many have pointed out, if you have given the service that was intended and asked by the buyer, please do not be handing out refunds. You will be undermining not only your own efforts, but you will also be encouraging such people to go around scamming more sellers this way. Do not be afraid of a few bad reviews, every successful seller will have them. I have a few, and yet I still have a 5-star on my profile because of the work that I did for many others who have appreciated it. Take pride in your work and do not bend your terms. Bad reviews from such clients can very easily be buried if you are not regularly messing up your orders by yourself. Also, try to verify your clients as much as possible before accepting order. I take in orders mostly through custom offers, so I’m not sure how much you can control that aspect if you take in orders through the order page, but you can try maybe.