How to report a client?

[caberte_cristine]

Hey guys! Can anyone help me? What should I do? A project milestone client has been unresponsive for almost a month now. Upwork approved my payment request on June 1st after 14 days not having heard from my client. Right now, my client contacted me via skype and wanted me to work for 18 more days because the contract was 30 days and I've only done 12 days. It wasn't my intention to stop cause he ghosted me for a month and took my access to the project I was working so I couldn't do anything but wait for him. He kept me waiting for more than a month and now he's telling me that I stole from him. He's also requested a refund.