What can I do?

Oh very sorry to hear that !I think if you are very nearest relative maybe you can speak out the reason, and keep know to each other . Maybe he need it very much and he can get from others , or maybe he have something hard to speak out .so don't get worried to much , all will goes up

Never do business with friends or family! This rule exists for a reason! In my opinion, all you can do unfortunately is cut your losses and learn from the experience. Once bitten twice shy..... I am sure that you will never do business with him again and why should you? Family and friends sometimes seem to be totally fine with taking liberties when it comes to business. It's sad but true.