It looks like the client requested a refund of the money they'd already released to you. You'll see the request in Messages. Please communicate with the client directly to try and resolve any issues amicably. If you agree to refund the money, you can issue the refund directly from the request in Messages. If you decide not to refund, the client may seek mediation assistance from Upwork. If that happens, Upwork team will reach out to you directly. You can check this help article for more information.