What would you do when it comes to this customer?

So I got a message from a customer. He bought 6 wax melts from me, and they were delivered the other day. He messaged me and this was the convo.

Him: None of the Yankee Candle Wax Melts Singles put out any scents.Must of been old ones.Not happy with my purchase of any of them.What can we do?

Me: I'm sorry you were unhappy with the purchase. I will gladly start the return process and provide a return shipping label for you to use and refund your purchase. Again, sorry about the melts.

Him: Wax Melts All been used.Nothing to return.Just want money back.Thats WHY everything got feedback.

When I looked, he gave me negative feedback for every individual one, bringing my 100% down to 96% in an instant. I'm wondering what I should do next. I'm kinda peeved all around by his attitude, the fact he doesn't have anything to return, and the feedback issue. If this were your situation, what would you do?