That sounds like a scam message. Roku devices themselves do not have a subscription, although certain channels do. Unless someone has hacked into your Roku user account, there's no way someone can do anything to disable your Roku devices. As a precaution, you should log into your Roku user account (https://my.roku.com) and change your password.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.