Cameras stopped working

One camera is a plug-in and the other is battery operated. I have installed fully charged batteries on the battery operated one but camera does not turn on. Sadly, it stopped working after the return grace period. The plug-in camera just stopped working. I’ve trouble shooter both following Ring guidance. I’d like to have these serviced as I have invested in multiple ring cameras and prefer to keep the service. How can I get these returned for service? Thank you.