Deauthorize a device not currently logged in

I've had several attacks by someone logging into my teamviewer account. They were even in my email so they could get the one to authorize their own device. I need to deauthorize the device but they aren't currently logged in. How do I remove those users? This is the third time that I know of with Hundreds of dollars in purchases made. Love teamviewer, but if this continues, I'll have to stop using completely.