How can we reduce the dispute rate?

We've received our first dispute on our plugin sales. After one year, the customer needs to pay for the plugin to continue using it. We will email him 7 or 5 days in advance. However, he wanted to take back his money. He said that he never receive any notification or email. He asked for a refund but we tried to explain. Then, he asked the bank to get back his money. Have you ever in similar situations? How do you deal with it?